Image-guide therapy of a tissue

ABSTRACT

Image-guided therapy of a tissue can utilize magnetic resonance imaging (MRI) or another medical imaging device to guide an instrument within the tissue. A workstation can actuate movement of the instrument, and can actuate energy emission and/or cooling of the instrument to effect treatment to the tissue. The workstation and/or an operator of the workstation can be located outside a vicinity of an MRI device or other medical imaging device, and drive means for positioning the instrument can be located within the vicinity of the MRI device or the other medical imaging device. The instrument can be an MRI compatible laser probe that provides thermal therapy to, e.g., a tissue in a brain of a patient.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application relates to and incorporates by reference thedisclosures of: U.S. Ser. No. 12/540,500, filed Aug. 13, 2009, publishedas US 2010/0042111; U.S. Ser. No. 12/540,558, filed Aug. 13, 2009,published as US 2010/0042112; PCT/IB2012/051716, filed Apr. 5, 2012,published as WO 2012/137179; U.S. Pat. No. 8,256,430, filed Dec. 17,2007, issued Sep. 4, 2012; U.S. Pat. No. 7,691,100, filed Aug. 25, 2006,issued Apr. 6, 2010; U.S. Pat. No. 7,344,529, filed Nov. 5, 2003, issuedMar. 18, 2008; U.S. Pat. No. 7,167,741, filed Dec. 14, 2001, issued Jan.23, 2007; and PCT/CA01/00905, filed Jun. 15, 2001, published asWO/2001/095821.

This application is a continuation-in-part of U.S. application Ser. No.13/838,310, filed Mar. 15, 2013, the content of each of which isincorporated by reference in its entirety. U.S. application Ser. No.13/838,310 claims the benefit of U.S. Provisional Application Ser. Nos.61/728,068, filed Nov. 19, 2012, U.S. 61/664,791, filed Jun. 27, 2012,and U.S. 61/759,197, filed Jan. 31, 2013.

BACKGROUND

In the following discussion certain articles and processes will bedescribed for background and introductory purposes. Nothing containedherein is to be construed as an “admission” of prior art. Applicantexpressly reserves the right to demonstrate, where appropriate, that thearticles and processes referenced herein do not constitute prior artunder the applicable statutory provisions.

Approximately 10% of cancerous brain tumors are “primary” tumors,meaning that the tumors originate in the brain. The primary tumorstypically consist of brain tissue with mutated DNA that aggressivelygrows and displaces or replaces normal brain tissue. The most common ofthe primary tumors are known as gliomas, which indicate cancer of theglial cells of the brain. In most instances, primary tumors appear assingle masses. However, these single masses can often be quite large,irregularly-shaped, multi-lobed and/or infiltrated into surroundingbrain tissue.

Primary tumors are generally not diagnosed until the patient experiencessymptoms, such as headaches, altered behavior, sensory impairment, orthe like. However, by the time the symptoms develop the tumor mayalready be large and aggressive.

One well known treatment for cancerous brain tumors is surgery. Surgeryinvolves a craniotomy (i.e., removal of a portion of the skull),dissection, and total or partial tumor resection. The objectives ofsurgery include removal or lessening of the number of active malignantcells within the brain, and a reduction in the pain or functionalimpairment due to the effect of the tumor on adjacent brain structures.However, by its very nature, surgery is highly invasive and risky.Furthermore, for some tumors surgery is often only partially effective.In other tumors, surgery itself may not be feasible. Surgery may riskimpairment to the patient, it may not be tolerable by the patient,and/or it may involve significant costs and recovery.

Another well known treatment for cancerous brain tumors is stereotacticradiosurgery (SRS). In particular, SRS is a treatment method by whichmultiple intersecting beams of radiation are directed at the tumor suchthat the point of intersection of the beams receives a lethal dose ofradiation, while tissue in the path of any single beam remains unharmed.SRS is non-invasive and is typically performed as a single outpatientprocedure. However, confirmation that the tumor has been killed orneutralized is often not possible for several months post-treatment.Furthermore, in situations where high doses of radiation may be requiredto kill a tumor, such as in the case of multiple or recurring tumors, itis common for the patient to reach the toxic threshold prior to killingall of the tumors, where further radiation is inadvisable.

More recently, the treatment of tumors by heat (also referred to ashyperthermia or thermal therapy) has been developed. In particular, itis known that above 57° C. all living tissue is almost immediately andirreparably damaged and killed through a process called coagulationnecrosis or ablation. Malignant tumors, because of their highvascularization and altered DNA, are more susceptible to heat-induceddamage than normal tissue. Various types of energy sources may be used,such as laser, microwave, radiofrequency, electric, and ultrasoundsources. Depending upon the application and the technology, the heatsource may be extracorporeal (i.e., outside the body), extrastitial(i.e., outside the tumor), or interstitial (i.e., inside the tumor).

SUMMARY

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key or essentialfeatures of the claimed subject matter, nor is it intended to be used tolimit the scope of the claimed subject matter. Other features, details,utilities, and advantages of the claimed subject matter will be apparentfrom the following written Detailed Description including those aspectsillustrated in the accompanying drawings and defined in the appendedclaims.

One exemplary treatment of a tissue includes interstitial thermaltherapy (ITT), which is a process designed to heat and destroy a tumorfrom within the tumor itself. In this type of therapy, energy may beapplied directly to the tumor rather than passing through surroundingnormal tissue, and energy deposition can be more likely to be extendedthroughout the entire tumor.

One exemplary ITT process begins by inserting an optical fiber into thetumor, wherein the tumor has an element at its “inserted” end that mayredirect laser light from an exterior source in a direction generally atright angles to the length of the fiber. The energy from the laser maytherefore extend into the tissue surrounding the end or tip and effectsheating. The energy may be directed in a beam confined to a relativelyshallow angle so that, as the fiber is rotated, the beam may also rotatearound the axis of the fiber to effect heating of different parts of thetumor at positions around the fiber. The fiber may be movedlongitudinally and rotated to effect heating of the tumor over a fullvolume of the tumor with the intention of heating the tumor to therequired temperature. This may be done, in some aspects, withoutsignificantly affecting the surrounding tissue. An exemplary fiber usedin the ITT process may be controlled and manipulated by a surgeon, inone implementation, with little or no guidance apart from the surgeon'sknowledge of the anatomy of the patient and the location of the tumor.In another implementation, medical images may be used to provideguidance when applying the controlled heating. For example, a locationof tumors and other lesions to be excised can be determined using amagnetic resonance imaging system (herein MRI). Utilizing MRI imaging inreal time guidance may provide controlled accuracy, whilecontemporaneous thermography may provide accurate temperatureinformation in determining whether a tissue has been ablated ornecrotized.

A system or method for effecting treatment to a tissue can include anautomated drive mechanism including a holder to hold a treatment device.The drive mechanism can be coupled to one or more wires or umbilicalssuch that a translation of the one or more wires or umbilicals effectsone or more of a longitudinal displacement of the holder and a rotationof the holder.

The system or method may include a controller that may include an inputinterface to process position control signals for setting a position ofthe treatment device, and may further include an output interface totranslate the one or more wires based on the position control signals.

The system or method may include a guide mechanism that may beattachable to a surface of a patient. The guide mechanism may include abase structure that may be configured to remain stationary relative tothe patient when the guide mechanism is attached to the surface of thepatient in a locked state. The guide mechanism may include a tiltportion that is coupled to the base structure. The tilt portion may bestructured so as to hold the drive mechanism at a position that isseparated from the surface of the patient. The tilt portion may providean adjustable tilt between a trajectory of the drive mechanism and thebase structure.

The guide mechanism may include a rotation portion that provides anadjustable rotation of the tilt portion relative to the base structure.The drive mechanism may be motorless and consist of thermal imagingcompatible components. The drive mechanism may not include an electricmotor, and may be included in an MRI or MRI head coil.

The controller may be configured to process a sequence of the positioncontrol signals to: move the holder to a first position for effectingthe treatment to the tissue at a first portion of the tissue thatcoincides with the first position; and move the holder to a secondposition for effecting the treatment to the tissue at a second portionof the tissue that coincides with the second position.

A workstation may be included to transmit the position control signalsto the controller and to display thermometry images of the tissue.

The workstation may continuously display the thermometry images of thetissue during the treatment to the tissue at the first and secondportions of the tissue, and while the holder moves between the first andsecond positions.

An energy emission probe may be the treatment device, wherein the probegenerates a plurality of different output patterns.

The probe may include a first laser fiber for outputting a symmetricaloutput pattern with respect to a longitudinal axis of the first laserfiber, and the probe may include a second laser fiber for outputting anasymmetrical output pattern with respect to a longitudinal axis of thesecond laser fiber.

In specific embodiments, the probe is coupled to a probe driver, whichallows the probe to be used to direct thermal energy to the targettissue and the heating of the target tissue is achieved by transmittingthe energy from a remote laser. The probe driver allows the energy to beemitted in multiple directions and at multiple depths without the needto provide additional physical access of the probe to the tissue. Theprobe driver allows the precise positioning, stabilization andmanipulation of a probe within a tissue target zone, either remotely ormanually. This allows additional target tissue to be accessed whileminimizing the invasiveness of the procedure.

In preferred embodiments, the probe driver is compatible with imagingsystems, including magnetic resonance imaging systems. In certainembodiments, the probe driver is robotic, and has the ability tocommunicate the probe's position and motion in the brain to a systemuser interface. Such a probe driver can be configured to be closefitting to the probe entry site (e.g., the skull). The lowered height ofthe probe driver allows a wider range of access within the probe entrysite, and the distal portion of the probe driver can be configured toattach directly to a bolt or other fastener that secures the probe tothe probe entry site. The probe driver can be connected, e.g., using asleeve or collar to secure the probe driver attachment to the probeand/or other devices. Allowing wider access to the target tissue with alow profile design allows the probe driver of the present invention tobe particularly well suited for procedures that require imaging, e.g.,neurological interventions that require imaging such as imaging withinan MRI device.

In a specific embodiment, the probe driver is comprised of a distalportion with a short stem. The stem can be mounted close to the probeentry site, and in specific embodiments the stem is mounted to a skullusing a device such as a bolt or other fastener. The height of thedistal stem of the probe driver is preferably designed so that it canaccommodate multiple trajectory devices to access different targettissues, allowing a wider range of the entry site to be accessed, e.g.,access to a wider range of skull. In specific embodiments, the probedriver may comprise a fiducial marker for visualization, either directlyattached through a compartment on the probe driver.

An energy source may be included to generate energy for the probe. Aworkstation may be included to transmit the position control signals tothe controller, and to transmit energy control signals to the energysource. The workstation may be configured to process a sequence of theenergy control signals to: effect a symmetrical treatment to the tissuewith the probe; and effect an asymmetrical treatment to the tissue withthe probe after the symmetrical treatment.

The system or method may include a laser source to generate laser energyfor the laser probe. The workstation may transmit the position controlsignals to the controller, and may transmit laser control signals to thelaser source. The workstation may be configured to process a sequence ofthe position and laser control signals to: move the holder to a firstposition for effecting the treatment to the tissue at a first portion ofthe tissue that coincides with the first position; effect a symmetricaltreatment to the first portion of the tissue with the first laser fiber;move the holder to a second position for effecting the treatment to thetissue at a second portion of the tissue that coincides with the secondposition; and effect an asymmetrical treatment to the second portion ofthe tissue with the second laser fiber.

The workstation may be configured to display thermometry images of thetissue continuously throughout processing of the sequence of theposition and laser control signals and throughout moving the holder andeffecting the symmetrical and asymmetrical treatments.

The system or method may include an imaging system to output images ofthe tissue and the treatment device, including thermometry images of thetissue, in real time, continuously throughout one or more steps ofeffecting the treatment to the tissue. The workstation may transmit theposition control signals to the controller based on one or more of theimages, as the images are received by the workstation in real time, andmay display, in real time, one or more of the images throughout the oneor more steps of effecting the treatment to the tissue.

The workstation may display, in real time, the thermometry images of thetissue with the images of the tissue and the treatment devicecontinuously throughout a processing of the position control signals andthroughout moving the holder and effecting the treatment to the tissue.

The workstation may process, in real time, the images of the tissue andthe treatment device and the thermometry images of the tissue toforecast errors or interruptions in the treatment to the tissue anddisplay a corresponding warning.

The system or method may include an energy emission probe as thetreatment device. The energy emission probe may include one or moreemitters selected from: a laser fiber, a radiofrequency emitter, ahigh-intensity focused ultrasound emitter, a microwave emitter, acryogenic cooling device, and a photodynamic therapy light emitter.

The energy emission probe may include a plurality of the emitters, wherethe plurality of the emitters may be longitudinally spaced with respectto a longitudinal axis of the energy emission probe.

The system or method may include a guide sheath including a plurality ofprobes of different modalities as the treatment device. The modalitiesmay include one or more of: laser, radiofrequency, high-intensityfocused ultrasound, microwave, cryogenic, photodynamic therapy, chemicalrelease and drug release.

The guide sheath may include one or more off-axis holes for positioningan emitting point of one or more of the plurality of probes at anoff-axis angle.

The system or method may include one or more processors and circuitsthat embody portions of aspects of various functions by executingcorresponding code, instructions and/or software stored on tangiblememories or other storage products. A display may include variousflat-panel displays, including liquid crystal displays.

The foregoing general description of the illustrative implementationsand the following detailed description thereof are merely exemplaryaspects of the teachings of this disclosure, and are not restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

No Color Drawings

A more complete appreciation of this disclosure and many of theattendant features thereof will be readily obtained as the same becomesbetter understood by reference to the following detailed descriptionwhen considered in connection with the accompanying drawings, wherein:

FIG. 1 is an illustration of exemplary relative locations of an MRIControl Room, an MRI Scan Room, and an MRI Equipment Room;

FIG. 2 is an illustration of a patient inserted into an MRI system;

FIGS. 3-4 illustrate components of an exemplary probe;

FIG. 5 illustrates a probe driver;

FIG. 6 illustrates an interface platform disconnected from a patientplatform of a stabilization system;

FIG. 7A illustrates a connector module being connected/disconnected toan interface platform;

FIG. 7B illustrates a connector module being connected/disconnected toan interface platform;

FIG. 8 illustrates a workstation;

FIG. 9 illustrates exemplary hardware of a workstation;

FIG. 10 illustrates a commander/interface platform engagement;

FIG. 11A illustrates a probe follower being aligned with a miniframe;

FIG. 11B illustrates a rotary test tool for a probe follower;

FIG. 12 is an exemplary screen shot of a display of an interfaceplatform;

FIG. 13 illustrates a ruler and depth stop of an exemplary probe;

FIG. 14 is an illustration of a commander/interface platform engagementwith a connector module;

FIG. 15 is a photograph of testing an output of a probe;

FIG. 16 illustrates sliding a probe into a probe follower;

FIGS. 17-19 illustrate an exemplary procedure overview including analgorithmic process that outlines portions of a procedure for treating apatient;

FIG. 20 is a perspective view of a portion of a miniframe;

FIG. 21 is a top plan view of a miniframe according to a firstrotational position;

FIG. 22 is a top plan view of a miniframe according to a secondrotational position;

FIG. 23 is a perspective view of a rotation portion of a miniframe in alocked configuration;

FIG. 24 is a perspective view of a rotation portion of a miniframe in anunlocked configuration;

FIG. 25 is a perspective view of a cam of a miniframe;

FIG. 26 is a perspective view of a frame of a miniframe;

FIG. 27 is a perspective view of a retaining ring of a miniframe;

FIG. 28 is a top perspective view of a central housing of a miniframe;

FIG. 29 is a bottom perspective view of a central housing of aminiframe;

FIGS. 30-31 illustrate an unlocked engagement between a central housingand a cam;

FIGS. 32-33 illustrate a locked engagement between a central housing anda cam;

FIG. 34 is a side profile view of a tilt portion of a miniframe in afirst tilt position;

FIG. 35 is a side profile view of a tilt portion of a miniframe in asecond tilt position;

FIG. 36 is a perspective view of a tilt portion of a miniframe in alocked configuration;

FIG. 37 is a perspective view of a tilt portion of a miniframe in anunlocked configuration;

FIGS. 38-39 are front and rear top perspective views of a locking arm;

FIGS. 40-41 are top and bottom perspective views of a locking arm and atilt portion in an unlocked position;

FIGS. 42-43 are top and bottom perspective views of a locking arm and atilt portion in a locked position;

FIGS. 44-45 are top and bottom perspective views of a tilt portion;

FIG. 46 is perspective view of a foot attached to a leg in an unlockedconfiguration;

FIG. 47 is perspective view of a foot attached to a leg in a lockedconfiguration;

FIG. 48 is perspective view of a foot;

FIG. 49 is perspective view of a foot attached to a spike plate;

FIG. 50 is perspective view of to a spike plate;

FIG. 51 is perspective view of a spike;

FIGS. 52-54 are, respectively, a bottom perspective view, a topperspective view, and a side view of a foot cap;

FIG. 55 is an illustration of a commander and an interface platform;

FIG. 56 is a schematic illustration of a knob of a commander coupled toa drive mechanism of an interface platform;

FIG. 57 is schematic cross section of a side-fire probe;

FIG. 58 is schematic cross section of a diffuse-tip probe;

FIGS. 59-70 illustrate profiles of exemplary types of probe tips;

FIG. 71A illustrates a schematic cross section of a probe in a guidesheath having an off-axis hole;

FIG. 71B illustrates a schematic cross section of a plurality of probesin a guide sheath having an off-axis hole;

FIG. 72 is a schematic illustration of a probe tip having a plurality oflongitudinally space apart energy emitters;

FIG. 73 is a schematic cross section of a side-fire probe and a diffusetip probe together in a common capsule;

FIG. 74 is a schematic cross section of a capsule attached to a laserfiber;

FIGS. 75-77 illustrate exemplary dimensions of components of anexemplary probe;

FIG. 78 is an illustration of a front perspective view of a patientplatform incorporating portions of a head fixation and stabilizationsystem;

FIG. 79 is an illustration of a side perspective view of a patientplatform incorporating portions of a head fixation and stabilizationsystem;

FIG. 80 is an illustration of a perspective view of a patient insertedinto an MRI, with a head fixation and stabilization system installed;

FIG. 81 is a schematic illustration of a head fixation ring attached toa patient's head;

FIG. 82 is a schematic illustration of one second half of a head coil;

FIG. 83 is a schematic illustration of another second half of a headcoil;

FIGS. 84-100 are exemplary screenshots of a graphical user interface ofa workstation;

FIG. 101 is an illustration of an algorithmic sequence for referencepoint selection, noise masking, and thermal shaping;

FIG. 102 is an exemplary embodiment of a skull-mounted bolt;

FIG. 103 is an exemplary follower of a probe driver;

FIG. 104 is an exemplary embodiment of the skull-mounted bolt;

FIG. 105A is a view of the exemplary follower;

FIG. 105B is another view of the exemplary follower;

FIG. 105C is another view of the exemplary follower;

FIG. 106A illustrates an exemplary embodiment in which a probe ismounted on a bolt; and

FIG. 106B illustrates an exemplary embodiment in which a probe ismounted on a miniframe.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

In the drawings, like reference numerals designate identical orcorresponding parts throughout the several views. Further, as usedherein, the words “a,” “an” and the like generally carry a meaning of“one or more,” unless stated otherwise.

Further, in individual drawings figures, the components/features shownare drawn to scale to exemplify a particular implementation. For somedrawings, components/features are drawn to scale across separate drawingfigures. However, for other drawings, components/features are shownmagnified with respect to one or more other drawings. Measurements andranges described herein relate to exemplary implementations and canidentify a value or values within a range of 1%, 2%, 3%, 4%, 5%, or,preferably, 1.5% of the specified value(s) in some implementations.

I. System and Workflow

System

A system in accordance with this disclosure incorporates magneticresonance imaging (MRI) compatible laser devices and accessories foreffective and controlled delivery of thermal therapy to a wide range oflocations and tumor sizes within a brain. The system, however, is notlimited to MRI-guided thermal therapy, as other therapies such ascomputer tomography (CT) can also be utilized. Further, this disclosurerefers to an MRI scanner as an exemplary medical imaging machine, whichmay be referred to simply as an MRI.

The system includes an interface platform (herein an interface platformor interface console), a system electronics rack and components (hereinrack), a control workstation (herein workstation), a probe driver, and aprobe. The system can also include a stereotactic miniframe, a head coiland stabilization system (herein stabilization system), an instrumentadaptor, and an MRI trajectory wand. All of the above components are MRIcompatible, which refers to a capability or limited capability of acomponent to be used in an MRI environment. For example, an MRIcompatible component operates and does not create significantinterference with MRI in exemplary magnetic flux densities of 1.5 T or3.0 T, where no hazards are known for a specified environment (e.g., 1.5T or 3.0 T). Compatibility can also be defined with respect to othermagnetic flux densities, including 0.5 T, 0.75 T, 1.0 T, 2 T or 5 T.“MRI Safe” refers to an item that poses no known hazards in all MRenvironments. “MRI Unsafe” refers to an item that is not MRI compatibleand is known to pose a hazard in MR environments. This equipment shouldnot be taken into the MRI room within a 5 Gauss perimeter line.

The interface platform attaches to an MRI patient table and providessupporting electronics for the probe driver and interconnections for theprobe. The system electronics rack includes necessary cables,penetration panels and small hardware for system mechanical, electrical,and electronic operation. The workstation includes a user interface,e.g., a graphical user interface (GUI), for procedure planning,interactive monitoring of procedures, and interfaces to the MRI andhardware subsystems. The probe driver allows for precise positioning,stabilization and manipulation of a probe. The probe can be a gas-cooledprobe for delivering controlled energy to a tissue. As discussed inSection IV, the length and diameter of the probe can be pre-selected andvaried.

The stereotactic miniframe includes at least a portion that is MRIvisible and used for trajectory determination, alignment, and guidanceof the probe. The stabilization system is a head fixation device toimmobilize a patient's head. The instrument adaptor can include a set ofthree reducing tubes of, e.g., 1.9±0.2 mm, 2.2±0.2 mm and 2.6±0.2 mm,that guide neurosurgical devices such as a biopsy needle through thestereotactic miniframe. The MRI trajectory wand is an MRI visible,fluid-filled tube which is placed into the stereotactic miniframe toallow trajectory confirmation of intended alignment to the target viaMRI.

Exemplary MRI systems that can be utilized together with the featuresdiscussed herein include those manufactured by Siemens AG, Munich,Germany (including the MAGNETOM AVANTO, TRIO, ESPREE, VERIO MRI Systems,which are trademarks and/or trade names of Siemens AG). Further,exemplary MRI systems include those manufactured by General ElectricCompany, Fairfield, Conn. (including the SIGNA, OPTIMA and DISCOVERY MRIsystems, which are trademarks and/or trade names of General ElectricCompany).

FIG. 1 illustrates an exemplary layout of various MRI components,including the MRI system in an MRI scan room, a control workstation inan MRI control room, and an electronics rack in an MRI equipment room.Also shown in FIG. 1 is an interface platform secured to a patient tableof the MRI system.

FIG. 2 illustrates an exemplary layout of a patient on a patient tableof an MRI system. An interface platform is secured to the patient tabletogether with a head coil and stabilization system. A probe and probedriver are coupled to a stereotactic miniframe, and to the interfaceplatform via umbilicals. A cable provides data, laser, fluid, etc.connections between these components and the electronics rack in the MRIequipment room.

The probe can be a laser delivery probe that is used to deliver laserinterstitial thermal therapy. The probe is preferably composed of MRcompatible materials allowing for simultaneous laser application andthermal imaging, and can be provided in multiple lengths and dimensions.FIGS. 3 and 4 illustrate exemplary aspects of a laser probe. Other typesof probes that can be utilized with the components and proceduresdiscussed herein include radiofrequency (RF), high-intensity focusedultrasound (HiFu), microwave, cryogenic, chemical release, which mayinclude photodynamic therapy (PDT), and drug releasing probes. Forexample, modalities of probes other than a laser energy modality can beutilized. Treatments in accordance with the descriptions provided inthis disclosure include treatments that ablate (i.e., “treat”) a tissueto destroy, inhibit and/or stop one or more or all biological functionsof the tissue. Ablation agents include, but are not limited to, laser,RF, HiFu, microwave, cryogenic, PDT and drug or chemical release. Acorresponding probe and/or an other instrument, such as a needle, fiberor intravenous line can be utilized to effect treatment by one or moreof these ablation agents.

A probe tip is shown in FIG. 3, which indicates an insertion end. Aprobe interface/depth stop adjustment provides an interface for cabling,as well as for alignment with the probe driver and/or the stereotacticminiframe. An end opposite the insertion end includes probe connectorsfor energy delivery, cooling, etc. FIG. 4 is an enlarged view of theprobe interface to probe tip portion of the probe shown in FIG. 3.

FIG. 5 illustrates a probe driver, which generally includes a commander,umbilicals, a follower, and a position feedback plug that receivesposition feedback signals from potentiometers within the follower. Aprobe can be inserted into the follower, and the follower can control arotational and longitudinal alignment of the probe.

The probe driver is mounted to the interface platform, as shown forexample in FIG. 2. A position feedback plug connects to the interfaceplatform in order to communicate the probe's position to the system. Theprobe driver is used to rotate or translate (extended or retract) theprobe. The probe driver in this illustrated implementation can provide,at a minimum, a translation of 20-80 mm, 30-70 mm, 40-60 mm or 40 mm,with a maximum translation of 60 mm, 80 mm, 100 mm, 120 mm or 60-150 mm.The probe driver in this illustrated implementation can also provide, ata minimum, a rotation of 300°-340°, with a maximum rotation of 350°,359°, 360°, 540°, 720° or angles therebetween. The probe driver iscomprised of the commander and the follower connected by an umbilicalcable (umbilicals). Included with the probe driver can be a rotary testtool that can be used during a self-test procedure to simulate anattachment of a probe to the follower.

FIG. 6 illustrates a coupling between an interface platform and a headend of a stabilization system. An attachment of the interface platformto the head end of the stabilization system can be performed by slidingtwo interface platform arms into two corresponding receptacles of thestabilization system.

FIGS. 7a-7b illustrate an interface platform connector module ofinterface platform, which is detachably connected to the interfaceplatform by a locking mechanism. This module is capable of acceptingprobe extension lines/cables. The connector module can be locked inplace by twisting the connector module lock 80-100° or 90°counterclockwise.

FIG. 8 illustrates an exemplary workstation situated in the MRI controlroom. The workstation can include an emergency stop (E-Stop) switch,which includes a red light to indicate that it is on (i.e., the presenceof the red light indicates the system and/or the MRI system has beenstopped via the emergency stop switch). To release the switch, theemergency stop switch can be twisted clockwise. The workstation can alsoinclude a power switch at the side of a monitor.

FIG. 9 illustrates an exemplary processing system, and illustratesexemplary hardware found in a controller or computing system (such as apersonal computer, i.e., a laptop or desktop computer, which can embodya workstation according to this disclosure) for implementing and/orexecuting the processes, algorithms and/or methods described in thisdisclosure. A processing system in accordance with this disclosure canbe implemented in one or more the components shown in FIG. 1. One ormore processing systems can be provided to collectively and/orcooperatively implement the processes and algorithms discussed herein.

As shown in FIG. 9, a processing system in accordance with thisdisclosure can be implemented using a microprocessor or its equivalent,such as a central processing unit (CPU) and/or at least one applicationspecific processor ASP (not shown). The microprocessor is a circuit thatutilizes a computer readable storage medium, such as a memory circuit(e.g., ROM, EPROM, EEPROM, flash memory, static memory, DRAM, SDRAM, andtheir equivalents), configured to control the microprocessor to performand/or control the processes and systems of this disclosure. Otherstorage mediums can be controlled via a controller, such as a diskcontroller, which can controls a hard disk drive or optical disk drive.

The microprocessor or aspects thereof, in an alternate implementations,can include or exclusively include a logic device for augmenting orfully implementing this disclosure. Such a logic device includes, but isnot limited to, an application-specific integrated circuit (ASIC), afield programmable gate array (FPGA), a generic-array of logic (GAL),and their equivalents. The microprocessor can be a separate device or asingle processing mechanism. Further, this disclosure can benefit fromparallel processing capabilities of a multi-cored CPU.

In another aspect, results of processing in accordance with thisdisclosure can be displayed via a display controller to a monitor. Thedisplay controller preferably includes at least one graphic processingunit, which can be provided by a plurality of graphics processing cores,for improved computational efficiency. Additionally, an I/O(input/output) interface is provided for inputting signals and/or datafrom microphones, speakers, cameras, a mouse, a keyboard, a touch-baseddisplay or pad interface, etc., which can be connected to the I/Ointerface as a peripheral. For example, a keyboard or a pointing devicefor controlling parameters of the various processes and algorithms ofthis disclosure can be connected to the I/O interface to provideadditional functionality and configuration options, or control displaycharacteristics. Moreover, the monitor can be provided with atouch-sensitive interface for providing a command/instruction interface.

The above-noted components can be coupled to a network, such as theInternet or a local intranet, via a network interface for thetransmission or reception of data, including controllable parameters. Acentral BUS is provided to connect the above hardware componentstogether and provides at least one path for digital communication therebetween.

The workstation shown in FIG. 8 can be implemented using one or moreprocessing systems in accordance with that shown in FIG. 9. Further, oneor more processors can be utilized to implement any functions and/oralgorithms described herein, unless explicitly stated otherwise. Also,the equipment rack and the interface platform each include hardwaresimilar to that shown in FIG. 9, with appropriate changes to controlspecific hardware thereof.

In some aspects, the workstation outputs signals to the MRI system toactuate particular imaging tasks or to an intermediary system thatcauses the MRI system to actuate particular imaging tasks. Further, insome aspects, the workstation outputs signals to the electronics rack.The electronics rack includes various actuators and controllers forcontrolling, e.g., a cooling fluid pressure and a flow rate of thecooling fluid, and a power source that outputs ablative energy. Inutilizing a laser probe, the power source is a laser source that outputslight via an optical fiber. As illustrated in FIG. 1, the electronicsrack is located in the MRI Equipment Room and includes storage tanks tohold the cooling fluid, one or more inputs to receive signals from thecontrol workstation and/or a separate MRI workstation, a lasergenerating device, and an output section. The output section includesdata and laser output cables that are routed to corresponding componentsin the MRI Scan Room through an appropriate portal to minimize interfacewith or by the MRI system. As discussed in other portions of thisdisclosure, the cables are connected at or by the interface platform tocorresponding components to effect and actuate control of thecomponents.

FIG. 10 illustrates the connecting of a commander to an interfaceplatform, and the attachment of a position feedback line and probe linesto the interface platform and/or the connector module thereof. In thesedrawings “IP” refers to the interface platform. The commander includesholes for mounting posts of the interface platform body, and a latch ofthe interface platform engages the commander when the commander isproperly inserted. Consistent with the descriptions provided in SectionIII, the commander includes knobs or dials that are coupled to a drivesystem of the IP. Command signals to actuate the drive system from,e.g., the workstation, are transmitted or routed to the IP, causing thedrive system to operate one or both of the knobs or dials to effectmovement of a probe or other member attached to the probe driverfollower in accordance with the disclosures provided herein.

FIGS. 11a and 11b illustrate a coupling between the follower, whichincludes directional interface tabs 1 and 2, and a stereotacticminiframe, which includes directional interface notches 1 and 2, toensure a proper registered alignment between the follower and thestereotactic miniframe. The miniframe also includes a directionalinterface locking thumbscrew to secure the follower to the miniframe.FIG. 11b illustrates the attachment of a rotary test tool to thefollower to provide position feedback for a probe driver self-testprocedure.

This self-test procedure can be executed via software that isdisplayed/illustrated to a user via the workstation and/or via theinterface platform. After attaching the commander of the probe driver tothe interface platform and the stereotactic miniframe, directionalcontrol and commands from the commander, the interface platform, and/orthe workstation can be verified with the rotary test tool.

For installation of the above components, the follower should be keptsterile and manipulated by a sterile person, while the commander can bepassed to a non-sterile person. The non-sterile person attaches thecommander to the interface platform and engages the latch to lock thecommander in place by twisting the latch to the centered position, asshown in FIG. 10. FIG. 10 further illustrates the attachment of aposition feedback line and probe lines to the interface platform and/orthe connector module thereof. In these drawings “IP” refers to theinterface platform. The commander includes holes for mounting posts ofthe interface platform body, and a latch of the interface platformengages the commander when the commander is properly inserted.

As illustrated in FIG. 11a , the sterile person slides the sterilefollower into the directional interface of the miniframe until thedirectional interface tabs are oriented and fully seated. The followeris then locked in place with the directional interface thumbscrew. Careshould be exercised when attaching the follower to the miniframe toprevent unintended trajectory deviation. This could lead to severeinjury or death of the patient. Additionally, the position feedback plug(cable) should be connected as shown in FIG. 10, and care should betaken to ensure that the cable for the plug does not rest on the patientduring imaging.

The following are warnings, cautions and/or issues that apply to thesystem described herein.

The system is indicated for use to ablate, necrotize, and/or coagulatesoft tissue through interstitial irradiation or thermal therapy inmedicine and surgery in the discipline of neurosurgery with 1064 nmlasers, when a thermal probe is utilized in the system. Lasers of otheroutputs can be utilized, including lasers having wavelengths of 0.1 nmto 1 mm, and lasers in one or more of the ultraviolet, visible,near-infrared, mid-infrared, and far-infrared spectrums. Types ofexemplary lasers include gas lasers, chemical lasers, dye lasers,metal-vapor lasers, solid-state lasers, semiconductor lasers, and freeelectron lasers. In one implementation, one or more wavelengths of thelaser is within the visible spectrum, and one or more wavelengths of thelaser is within the near-infrared spectrum. The system can be utilizedfor planning and monitoring thermal therapies under MRI visualization,and can provide MRI-based trajectory planning assistance for thestereotactic placement of an MRI compatible (conditional) probe. It alsoprovides real-time thermographic analysis of selected MRI images.

When interpreted by a trained physician, this system providesinformation that may be useful in the determination or assessment ofthermal therapy. Patient management decisions should not be made solelyon the basis of an image analysis.

Probe or laser delivery in highly vascular regions can result inhemorrhage and/or post treatment aneurysm. Probe trajectories whichtransect or overdosing with thermal energy in regions containingcortical-spinal pathways can result in patient injury and permanentneurological deficits. Protracted surgical sessions with the patientimmobilized can result in deep vein thrombosis.

The system should be operated by trained personnel under the directsupervision of a trained physician. Laser eye protection should be wornin the MRI scanner room during operation of a laser. The colorperception abilities of an operator should be considered duringtemperature monitoring in implementations that utilize color maps, wherethe monitoring is manually performed by the operator. Operators who arecolor blind or have impaired color perception may not be able to monitortemperature during the procedure which could result in patient injury ordeath. Only approved accessories should be used. Failure to do so mayresult in improper performance and/or damage to the equipment withpotential to cause harm. Only approved and verified MRI sequences forthermal imaging should be used in conjunction with this equipment.Failure to do so may result in improper thermal monitoring which couldlead to patient injury.

All loaded image data should contain correct patient identification andimage orientation markers prior to the commencement of a procedure toensure an unintended area of the brain is not targeted for thermaldelivery which can lead to patient injury.

Extreme care should be taken when determining patient baseline core bodytemperature by using an MRI compatible patient monitoring system usingan internally placed temperature monitoring probe. Failure to determinean accurate value will result in improper performance of temperaturemonitoring software with the potential to cause patient injury. During aprocedure, the treated tissue should be allowed to return to ambienttemperature levels before acquiring subsequent MR thermal imaging.

The system may be contraindicated for patients with certain metallic,electronic or mechanical implants, devices or objects that should notenter the MRI scan room or serious injury may result.

Further, the user should beware of the strong magnetic field in the MRIroom. Extreme caution should be used before bringing in any equipmentinto the MR environment. Only items identified as MR Safe orCompatible/Conditional for the particular environment should be broughtinto the MR room. No items identified as MR Unsafe should be broughtinto the MR suite within the 5 Gauss line. Serious injury can result ifany equipment which is MR unsafe is brought into the MRI suite.

The following are specific warnings that apply to the probe driver andthe probe.

These components are intended for single use, and should not be reused,reprocessed or re-sterilized. Reuse, reprocessing or re-sterilizationcan compromise the structural integrity of the device and/or lead todevice failure which in turn may result in patient injury, illness ordeath. Reuse, reprocessing or re-sterilization may also create a risk ofcontamination of the device and/or cause patient infection orcross-infection, including, but not limited to, the transmission ofinfectious disease(s) from one patient to another. Further,contamination of the device may lead to injury, illness or death of thepatient.

When aligning and connecting the probe driver follower, the user shouldconfirm that the position displayed on the interface platform iscorrect. Failure to do so may cause the laser energy delivery directionto be determined incorrectly, potentially resulting in patient harm.

All cables and umbilical in the vicinity of the MRI bore should not formloops as this may result in heating (with the potential to cause burnsto the patient) and RF interference (which would affect equipmentperformance). The probe should be fully engaged to the probe driverprior to manipulating the probe in tissue. The laser in the probe shouldnot be fired if the probe is not inserted in tissue or before the probeconnections are made. A desired probe trajectory should be ensured tonot interfere with the MR bore or other required equipment prior to theinsertion of the probe into tissue.

The probe can classified as a class 4 laser product in accordance withEN60825-1:2003. Irreversible injury can occur. Laser radiation shouldnot be directed to the retina of the eye. Skin or the eye should not besubjected to direct or reflected laser radiation. Each person inside thelaser area should wear protective eyewear.

Laser fiber connections should be made correctly as improper connectionscan lead to fire danger or operator injury. Laser connections should befully seated. Failure to do so can cause the receptacle to heat, reducethermal energy deposition, cause equipment damage or operator or patientinjury.

The laser area can be defined by the Nominal Ocular Hazard Distance(NOHD) as 2.8 m from the laser output at the probe tip (when connected)or the extension fiber output on the interface platform. Outside of thisregion, laser safety eyewear is not required.

An exemplary probe and probe driver can be used under the followingconditions: static magnetic field of 1.0, 1.5, 2.0, 2.5, 3.0 or 3.5Tesla; and spatial Gradient field of 500, 360, 300 or 240 Gauss/cm orless. The whole-body-averaged specific absorption rate (SAR) should notexceed 4, 3, 2, 1.5 or 1 W/kg. Whole body transmitting coils can beused. Local transmitting coils should not be used, but local receivingcoils can be used.

MRI image quality may not be affected while the interface platformdisplay is OFF. However, image quality can be affected if the interfaceplatform display is powered ON during acquisition, potentially causingimage artifacts.

The probe and probe driver should be inspected carefully prior to usefor any breach of the sterile barrier or damage to the contents, andshould not be used if the sterile barrier integrity is compromised orthe contents damaged.

General preferred operating conditions of the system include:temperature: 15° C. (59° F.) to 30° C. (86° F.) or around 23-26° C.; andrelative humidity: <50, 60 or 70%. General preferred storage conditionsof the system include: temperature: 10° C. (50° F.) to 40° C. (104° F.);relative humidity: <60%; and keep out of direct sunlight.

The system can use medical grade CO2 gas as a coolant for a laser probe.Medical grade CO2 size “E” tanks, unless otherwise labeled, are MRUnsafe and should not be brought into the MR suite within the 5 Gaussline. The electronics rack can be designed to hold two “E” size tanks.For a particular implementation, pressure gauges for each tank shouldread >4500 kPa (>650 psi) for use. Exemplary pressures of the gasinclude 600-650, 650-700, 700-750, 750-800, 800-850 and 700-900 psi.

Procedure Workflow

A procedure includes, generally, identifying a tissue in a patient to betreated, planning one or more trajectories for treating the tissue,preparing the patient and components for the treatment, and performingthe treatment. Aspects of the various parts of the treatment aredescribed throughout this disclosure, and a particular sequence oftreatment steps is described herein.

In pre-planning of a treatment of a patient, pre-treatment DICOM imagedata is loaded and co-registered via the workstation. An intendedtreatment region of interest(s) (ROI)(s) and initial trajectory(s) arecreated and established as desired.

A head coil and fixation system is attached to the patient, whichincludes positioning the head coil and stabilization system on thesurgical table. The patient is immobilized using a head fixation ring.The patient head should be secured with a head fixation device andremain fixed within magnet space for entire imaging portion of theoutlined workflow. If the patient head position changes relative to thehead fixation device at any point during the procedure, then new imagingshould be acquired and co-registered as a master series or thermalenergy may be delivered in an unintended area causing patient injury.

A probe entry location into the skull is identified, and a burr hole maybe created prior to miniframe attachment or a twist-drill hole should becreated following stereotactic miniframe trajectory alignment. Thetwist-drill hole can have a size of 1-5 mm, 2 mm, 3 mm, 4 mm or 4.5 mm.The stereotactic miniframe is attached to the patient's head, and theminiframe is aligned along the intended trajectory using image-guidednavigation. The head coil and fixation system is then attached.

Depending on a site specific workflow, the interface platform may beattached prior to or after MRI trajectory confirmation. The order ofthese steps is typically determined with the MRI or surgical supportteam during on-site training. The interface platform is attached to thehead end of the head coil and stabilization system, as shown in FIG. 6.Then, the IP power and motor plugs are connected, as shown in FIG. 10.

Trajectory confirmation and beam fiducial marker detection is thenperformed. The established trajectory of the miniframe should beevaluated using MRI prior to inserting a probe into the brain.Volumetric imaging is recommended to include the entire head and fullextent of the miniframe. These images will also visualize a beamfiducial marker located in a portion of the miniframe. This marker isidentified to orient the software to the physical direction of theprobe. This image data can also be used for treatment planning ifpre-treatment image data is not available.

The patient is positioned in the MRI, and MRI imaging is performed toconfirm trajectory with an MRI trajectory wand inserted into theminiframe.

Using the workstation within a so-called “Plan Register” workflow step,acquired image data is loaded and co-registered with already loadedpre-planning image data (if any). Using the workstation within aso-called “Plan Volumes” workflow step of the workstation, treatmentROI(s) are defined, if not already defined. Using the workstation withina so-called “Plan Trajectories” workflow step, a rendered probetrajectory(s) along the imaged position of the MRI trajectory wand isestablished and/or adjusted. Using the workstation within a Treat Alignand Auto-Detector step, the fiducial marker of the miniframe isidentified/registered and set.

The follower is attached to the miniframe, and the rotary test tool isattached to the follower to provide position feedback for a probe driveself-test step, which confirms that inputs to the follower, via thecommander, accurately drive the rotary test tool. Once successful, therotary test tool is removed by depressing a release button on its sideand pulling it back off of the follower. See FIG. 11b . Upon removal oftest tool, the rotary position will no longer be valid and will bedisplayed on the interface platform as “Unset” until the probe is placedinto position.

An appropriate probe size is selected, and a corresponding probe isremoved from its sterile pouch and placed in the sterile field.

The following steps are taken to set and lock a probe depth stop. Theworkstation calculates the required length of the probe based ontrajectory planning and the intended target. The interface platformdisplays the probe size for the user in two ways during a systemself-test, as shown in FIG. 12, which includes an image of a displayscreen of the interface platform. FIG. 12 illustrates a required probesize and depth stop setting.

FIG. 13 illustrates adjustment and setting of a depth stop. A first stepis to ensure a probe is fully inserted into the ruler/protective cover,as shown in FIG. 13. An audible click should be heard if reinserting thecover into the probe locking interface. The locking interface is thenslid so that the probe tip aligns with the required distance measurementon the ruler. Locking buttons at the wider end are then squeezed to lockthe depth stop, as shown in FIG. 13. An audible click should be heardwhen locked. A tapered part/end of both buttons can be squeezed tounlock the depth stop lock.

The proper depth of the probe can be rechecked by matching the probe tipto ruler graduations. Further, it should be rechecked that the depthstop is locked prior to inserting the probe into the brain. Animproperly set depth stop can allow the probe tip to be delivered shortof or deeper than intended/planned, which may lead to patient injury.The ruler is then removed by depressing the release button shown in FIG.13.

FIG. 14 illustrates the location of probe connections on the interfaceplatform. Preferably, the sterile person will hand off the probeconnector plugs to a non-sterile person to insert the plugs to theassociated receptacles on interface platform. The cooling plug isinserted into the mating receptacle (labeled CO2). It should click andlock when fully inserted. The arrow on the thermocouple plug should bealigned with the arrow on the receptacle marked THERMOCOUPLE. The plugshould be inserted into the receptacle until it clicks and locks. Thelaser plug should be inserted into the mating receptacle (labeledLASER). Two clicks should be heard; one at half insertion and one atfull insertion. With medium force, the connector should be pulled backto ensure it is fully seated and does not pull out. The three connectorlines in the connector line bracket should be retained as shown in FIG.14 to ensure that the lines remain fixed to the interface platform ifthe specific site that the workflow so requires.

The laser probe laser fiber connector should be completely engaged intothe corresponding interface platform receptacle. Failure to do so cancause receptacle heating and reduce the energy delivered to the targettissue. This may result in fire or injury of the user or patient.

The three probe connector lines should be retained in the probeconnector line bracket to ensure potential force during disconnection ofthe probe connectors is not transferred to the probe after insertioninto the brain. Force applied to the probe after insertion into thebrain can lead to patient injury or death.

The laser is physically interlocked by the workstation until theappropriate workflow step has been reached. The laser interlocks shouldremain disabled throughout the workflow until treatment monitoringbegins. However, the visible pilot laser beam can be enabled. Thevisible pilot laser can be a class 2 laser product according to IEC60825-1 having a maximum power of 1 mW. Other maximum powers include0.5, 0.6, 0.7, 0.8, 0.9, 1.5 and 2-5 mW. The laser should not emitenergy when a foot pedal is pressed during a self test. A bright, redlaser light should be visible exiting the probe tip in the correctorientation from the probe. Aiming the beam at a surgical glove shouldproduce a bright, red spot, as shown in FIG. 15. If the physician or auser does not see a strong, visible red aiming laser beam exiting theprobe tip, then the full insertion of the probe laser plug should beensured. Otherwise, the probe should be disconnected, and a second probeof the same size should be selected and registered as the first probewas.

When the beam test is successful, a next button can be depressed on theinterface platform display to continue the workflow steps shown on theinterface platform display. A gas cooling test can then begin. The Nextbutton can be depressed when it has completed.

The tip of the probe can then be inserted into the probe driver followerand into the brain until the probe locking interface comes in contactwith a mating adapter on the follower. See FIG. 16. While gentlypressing the probe toward the follower, the probe can be twisted untilit fully locks onto the follower. An audible click should be heard whenthe probe is locked into position. This can be confirmed by gentlypulling back on the probe to ensure it is properly locked in place,which is shown in FIG. 16.

MRI imaging is performed to confirm delivery of the probe along theintended trajectory. Acquired image data with already loadedpre-planning image data (if any) can be loaded using a Treat Insertworkflow step of the workstation. The rendered probe in the workstationcan then be adjusted as needed to match the probe artifact on theacquired image. Once the software rendered probe matches the probeartifact on the screen, “Yes” or “Confirm” can be selected through theworkstation to confirm trajectory.

In advance of each procedure, a data transfer interface should beenabled following patient registration on the MRI system. If the patienthead position changes relative to the head fixation device at any pointduring the procedure the user should either register the patient in theMRI system as a new exam or use the MRI positioning lights to“re-landmark” the patient into magnet space center position. The entirehead should be re-scanned to include the miniframe using a 3D volumetricscan. This scan should be co-registered with all other loaded planningsequences and be set as the master or thermal dose may be delivered inan unintended area causing patient injury.

Using the workstation, the rendered probe's trajectory can be adjustedto the desired linear position for thermal delivery. The renderedprobe's rotary position can also be adjusted to the desired direction(angle) for thermal delivery. A scan plane can be selected undermonitoring preferences of the workstation, and a thermal monitoringsequenced can be cued MRI system's sequence protocol list. The displayedscan plane parameters can be entered into the thermal monitoringsequences protocol's geometry parameters in the MRI.

An acquisition can then be started under a monitoring status bar of theworkstation interface, and a thermal monitoring sequence on the MRI canbe acquired. Under a noise masking heading of the workstation interface,3 to 12, 4, 5, 6, 7, 9, 10, 11, 13 or 15-25 references points, such as 8reference points, can be selected at the periphery of the overlaid,orange noise mask in each of the three displayed image monitoringview-panes surrounding the intended thermal delivery area.

Once “Ready” is displayed under a laser status heading, a foot peddle ofthe workstation can be depressed to deliver thermal energy to theintended area of the brain. Thermal energy can the be continuouslydelivered while monitoring created thermal dose contours overlaid ontothe three thermal monitoring view-panes on the display screen of thework station. Thermal delivery can be stopped when desired by releasingthe foot peddle.

The MRI is allowed to continue to acquire the thermal monitoringsequence until the tissue returns to baseline body temperature. Stopacquisition can then be selected through the workstation to stopacquiring the thermal monitoring sequence on the MRI. These steps canthen be repeated until a desired thermal dose is received by the entire,intended volume of tissue.

An exemplary procedure overview is shown in FIGS. 17-19, which includesalgorithmic, computer-implemented processes and/or functions, togetherwith operations performed by a user, technician, nurse and/or surgeon(or other physician or assistant). The steps shown herein generallyinclude one or more sub steps consistent with the other portions orsections of this disclosure.

At S102, anesthesia is given to a patient. Anesthesia includes generaland/or local anesthesia to sedate or put the patient under. Theanesthesia may also merely numb or relieve pain, in someimplementations. The patient's head is then fixated at S104. Before headfixation, a head coil and stabilization system can be utilized, asdiscussed in other portions of this disclosure. For example, aparticular head coil and stabilization system is described in Section V.

The operation area of the patient's head is then draped to create asterile field at S106. Such draping can include the placement of patchesor sheets on and/or around the patient's head to minimize exposure andthe chances for infection. After the sterile field has been established,a miniframe is attached to the patient's head at S108. A particularminiframe in accordance with this disclosure is described in Section II.The miniframe is aligned at S110. A probe entry location into the skullis identified, and a burr hole may be created prior to miniframeattachment or a twist-drill hole can be created following stereotacticminiframe trajectory alignment. The twist-drill hole can have a size of1-5 mm, 2 mm, 3 mm, 4 mm or 4.5 mm.

In this alignment, the trajectory and miniframe are adjusted so as toconform with a pre-planned trajectory for the insertion of a probe orother instrument into the patient's skull. Alignment at S110 can alsoinclude visual-based stereoscopic alignment with the assistance ofthree-dimensional renderings in an operating room. Such alignment canutilize instruments that include fiducial markers that specificallyidentify a three-dimensional position of the instruments relative to thepatient's skull. Markers can include electronic (e.g., RFID—radiofrequency identification) markers and/or visual markers.

At S112, the interface platform is attached to the head end of a headcoil and stabilization system, as shown in FIG. 6, the patient is placedin an MRI, and a pre-planning procedure commences. The stabilizationsystem can be attached to the patient on a patient table that moves withthe patient between various rooms (including a surgical room, anoperating room, and the MRI room). The patient can be immobilized usinga head fixation ring. The patient's head should be secured with a headfixation device and remain fixed within the magnetic space for theentire imaging portion of the outlined workflow. In advance of eachprocedure, a data transfer interface should be enabled following patientregistration on the MRI system. If the patient head position changesrelative to the head fixation device at any point during the procedurethe user should either register the patient in the MRI system as a newexam or use the MRI positioning lights to “re-landmark” the patient intomagnet space center position. The entire head should be re-scanned toinclude the miniframe using a 3D volumetric scan. This scan should beco-registered with all other loaded planning sequences and be set as themaster or thermal dose may be delivered in an unintended area causingpatient injury. The head coil can be attached to the stabilizationwithin the MRI room or in an operating room.

At S114, as part of a pre-planning procedure, image data is loaded fromthe MRI and a volume definition is generated and co-registered via theworkstation at S116. Intended treatment region(s) of interest (ROI)(s)and initial trajectory(ies) is/are created and established as desired atS118. At the same time as the pre-planning procedure or after thetrajectory definition is generated at S118, the MRI trajectory isconfirmed at S120. This MRI trajectory can be confirmed via a wand thatincludes a material, such as a liquid, that is visible in the MRI image.The wand can be placed in the miniframe. Depending on a site specificworkflow, the interface platform may be attached prior to or after theMRI trajectory confirmation at S120. The order of these steps istypically determined with the MRI or surgical support team duringon-site training. Then, the IP power and motor plugs are connected, asshown in FIG. 10. Image data is then loaded and the trajectory isregistered therewith at S122.

The miniframe includes fiducial markers that are detectable by the MRIsuch that image data includes the fiducial markers of the miniframe, andsuch that a position and orientation of the miniframe can be registeredand detected by a workstation. At S124, the fiducial markers of theminiframe are detected by the MRI such that a position and orientationof the miniframe can be registered by a workstation. The establishedtrajectory of the miniframe should be evaluated using MRI prior toinserting a probe into the brain. Volumetric imaging is recommended toinclude the entire head and full extent of the miniframe. This imagedata can also be used for treatment planning if pre-treatment image datais not available.

At S126, a maximum probe depth (PDP) is set. This maximum probe depth isset to reduce chances of inserting a probe or other instrument furtherinto tissue of the patient than as previously planned, which can causeunintended damage to the tissue. An initial probe insertion depth is setat S128. Further aspects of the above pre-planning and setting and/orregistration of probe depth and miniframe alignment are described in aparticular implementation in Section VI.

A system self test commences at S130. This system self test can confirmoperation and positioning of the various components discussed above. AtS132, a foot pedal of the workstation is checked to confirm the footpedal activates operation of, for example, a laser probe. At S134, aprobe driver is attached to the miniframe, and alignment and positioningof the probe driver is checked with the workstation. Further, operationof the probe driver is verified. A particular implementation of a probedriver is described in Section III. A follower is attached to theminiframe, and a rotary test tool is attached to the follower to provideposition feedback for a probe drive self-test step. Once the self-teststep is determined as successful, the rotary test tool is removed bydepressing a release button on its side and pulling it back off of thefollower, as illustrated in FIG. 11b . Upon removal of the test tool,the rotary position will no longer be valid and will be displayed on theinterface platform as “Unset” until a probe is placed into position.

A probe is attached and inserted into the probe driver and/or thepatient's skull at S136. Particular implementations of the probe aredescribed in Section IV. However, other types of probes or instrumentscan be utilized. Once an appropriate probe size is selected, acorresponding probe is removed from its sterile pouch and placed in thesterile field.

At S138, an MRI scan is conducted to ensure probe placement is correctand confirm delivery of the probe along the intended trajectory.Acquired image data with already loaded pre-planning image data (if any)can be loaded using a corresponding function (e.g., a graphical userinterface) of the workstation. The rendered probe in the workstation canthen be adjusted at S140 as needed to match the probe artifact on theacquired image to ensure that the alignment and arrangement of the probeas physically placed in the miniframe and inserted into the patientcoincides with the rendered probe at the workstation. The renderedprobe's trajectory can be adjusted to the desired linear position forthermal delivery. Further, the rendered probe's rotary position can alsobe adjusted to the desired direction (angle) for thermal delivery. Oncethe software rendered probe matches the probe artifact on the screen,“Yes” or “Confirm” can be selected through the workstation to confirmtrajectory. A scan plane can be selected under monitoring preferences ofthe workstation, and a thermal monitoring sequence can be cued MRIsystem's sequence protocol list. The displayed scan plane parameters canalso be entered into the thermal monitoring sequences protocol'sgeometry parameters in the MRI. Other aspects of this interface with theworkstation is discussed in Section VI.

Treatment of a tissue can then commence, starting with setting upreal-time transfer of MRI data, specifically imaging data, to theworkstation at S142. At S144, real-time measurements can begin, and atS146, temperature calculation measurements can be set up and monitored.At this time, several images of a tissue to be treated are visible to auser at the workstation, and a probe is ready to be fired or activatedto emit laser energy, for example, to the tissue to be treated. Under anoise masking heading of the workstation interface, eight referencepoints can be selected at the periphery of the overlaid, orange noisemask in each of the three displayed image monitoring view-panessurrounding the intended thermal delivery area. Once “Ready” isdisplayed under a laser status heading, a foot pedal of the workstationcan be depressed to deliver thermal energy to the intended area of thebrain. Thermal energy can the be continuously delivered while monitoringcreated thermal dose contours overlaid onto the three thermal monitoringview-panes on the display screen of the work station. Thermal deliverycan be stopped when desired by releasing the foot pedal. At S148, thethermal dose of the laser is monitored, and effective treatment can bemonitored. Further aspects are described in Section VI.

Once a thermal dose for a particular alignment and positioning of theprobe is determined, the probe can be rotated at S150, and thermal dosemonitoring at S148 can be repeated with various probe rotationalignments. Lasing (laser output) can then be terminated at S152, andthe probe can be subjected to linear travel at S154 to various linearpositions for creating an effective treatment region that is shaped tothe to-be-treated tissue portion, by repeating steps S142-S154. Rotationand linear travel of the probe can be controlled by a probe driver, aparticular implementation of which is described in Section III. The MRIis allowed to continue to acquire the thermal monitoring sequence untilthe tissue returns to baseline body temperature. “Stop acquisition” canthen be selected through the workstation to stop acquiring the thermalmonitoring sequence on the MRI. These steps can then be repeated until adesired thermal dose is received by the entire, intended volume oftissue.

Once treatment is completed the patient can be removed from the MRI boreat S156, and the probe and probe driver can be removed at S158. At thistime, if another probe or probe driver is to be used, the procedure canbe repeated by returning back to S110 to align the miniframe trajectoryof the new probe and/or probe driver. Otherwise, the miniframe can beremoved at S160, and the patient can be closed at S162.

In light of the descriptions provided herein:

An adjustable device, a miniframe, is provided that allows for a movableprobe tilt point spaced apart from patient's head, while the miniframeis affixed to the patient's head. A probe attached to the miniframe canbe advanced (laterally displace and/or rotated) under MRI guidance.

The head coil and stabilization system can fixate a patient and permitthermometry around substantially an entire crown line of the patient. Inconjunction with the miniframe, steep and shallow probe insertion anglesare available.

Multiple different probes can be utilized and swapped in the MRI room soas to provide different ablation patterns from different probes. Forexample, a symmetrical ablation probe can be used, followed by aside-fire (asymmetrical) ablation probe. A diffused tip probe can alsobe utilized.

A process of advancing probe, asymmetrically ablating, measuring,advancing probe and repeating is provided, such that the process doesnot require the interruption of a user-intervention in the MRI room tochange probes or probe position.

Further, alterations to the procedures discussed herein can include thefollowing:

The miniframe can be affixed in a preparation room, then placed in theMRI, and then the trajectory of the miniframe can be set in thepreparation room. The hole can be drilled in the preparation room, andthe patient can then be returned to the MRI for ablation procedure. Thismay proceed without an operation room (OR). The trajectory can also beoptionally set based on images taken immediately prior to an ablation ortreatment procedure. Further, a single burr hole and trajectory can beutilized by the use of family of probes. The procedure(s) can optionallybe conducted without general anesthesia.

The miniframe provides a movable pivot or tilt point above a target,i.e., above the patient's head. The probe driver is attached to theinterface platform, as shown in FIG. 10, allowing control of movement ofa probe or other implement attached to a probe driver follower to berotated or longitudinally moved. Thus, a movable pivot or tilt pointabove a target is provided for a probe or other implement, which can beadvanced or rotated under MRI guidance, through control by an operatoror a workstation that is located in a separate MOM.

A trajectory can be set, after the miniframe and head stabilizationsystem are attached to a patient, by utilizing an MRI to visualize atrajectory of the miniframe and set/register/lock the miniframe and/orthe head stabilization system to an appropriate alignment. Then, a burrhole can be drilled in a prep room using the registered miniframe. Thepatient is then returned to the MRI for treatment procedures.

In some aspects, one or more burr holes, the head fixation components,and the miniframe are attached without the use of an operating room.

The trajectory can be adjusted immediately prior to a treatmentprocedure (e.g., an ablation procedure), based on recent MRI imaging.

Consistent with Section IV, a plurality of trajectories and/or probescan be inserted into a single burr hole. Also, pursuant with Section IV,a plurality of probes can be utilized with a single trajectory and asingle burr hole.

II. Miniframe

The miniframe in an implementation coincides with the framelesstrajectory guide described in US 2010/0042111, which is incorporatedherein by reference in its entirety. The miniframe can also be modifiedto conform with the examples shown and discussed herein.

FIG. 20 illustrates a miniframe 200, which can also be referred to as aframeless trajectory guide or simply as a trajectory guide. Theminiframe 200 includes a tilt portion 202 and a rotation portion 204.The miniframe 200 also includes a plurality of legs 206.

FIGS. 21 and 22 illustrate two different rotational positions of therotation portion 204. As shown in FIGS. 21 and 22, a rotation of therotation portion 204 does not necessarily change the actual trajectoryof the a through hole 208 of the tilt portion 202, through which aninstrument, such as a probe, is insertable therein. The through hole 208includes two alignment guides 264. These alignment guides 264 allow forproper pre-determined alignment between a probe and/or a probe followerand the miniframe 200.

Rotation of the rotation portion 204 can be locked via a cam 210. FIG.23 illustrates a locked position of the cam 210, whereas FIG. 24illustrates an unlocked position of the cam 210. In the unlockedposition, the rotation portion 204 is free to rotate. On the other hand,in the locked position, the rotation portion 204 is inhibited or stoppedfrom being rotated.

FIG. 25 illustrates an exemplary cam in accordance with the shownimplementation. The cam 210 includes a plurality of teeth 212. Theseteeth 212 are structured so as to engage corresponding teeth of therotation portion 204, discussed below.

The rotation portion 204 includes a frame 214. The frame 214 includes aplurality of mounts 216 that are arranged so as to be coupled to thelegs 206. Further, the frame 214 includes a cam mount 218 that isarranged to receive the cam 210.

FIG. 27 illustrates a retaining ring 220, which includes a tab portion222 and a plurality of alignment markings 224. The tab portion 222 isarranged so as to coincide with the cam mount 218 and the cam 210, asshown in FIGS. 23 and 24, for example. Further, the tab portion 222provides a rotational stop to limit rotation of movement of the cam 210,as shown in FIG. 24, by example.

FIGS. 28 and 29 illustrate top and bottom perspective views of a centralhousing 226 of the rotation portion 204. The central housing 226includes a plurality of teeth 228 that are arranged to engage thecorresponding teeth 212 of the cam 210.

The engagement and non-engagement of the cam 210 to the central housing226 is illustrated in FIGS. 30-33. FIGS. 30-31 illustrate an unlockedengagement, where the rotation portion 204 is free to rotate. FIGS.32-33 illustrate a locked engagement in which the teeth 212 of the cam210 create a locking engagement with the teeth 228 of the housing 226,as shown by the underside view of FIG. 33.

With the above locking mechanism provided by the cam 210 and the housing226, relative rotation between the rotation portion 204 and the frame214 is inhibited. The frame 214 is mounted via the legs 206, where thelegs 206 provide an initial trajectory, which is defined by a placementof the legs 206, a length of the legs 206, and initial positions of therotation portion 204 and the tilt portion 202. In one implementation, atilt angle of the tilt portion 202, a rotation angle of the rotationportion 204, and lengths and placements of the legs 206 are set to apre-planned trajectory, and the miniframe is 200 mounted to a patient'sskull. For example, the rotation angle of the rotation portion 204 andthe lengths and placements of the legs 206 can be set, and then theminiframe is attached to the patient. Thereafter, the tilt angle of thetilt portion 202 is set.

FIGS. 34 and 35 illustrate two different exemplary tilt angles of thetilt portion 202. Together, the tilt portion 202 and the rotationportion 204 can form a spherical shape, in which rotation and tilt areindependently controlled and independently locked. The above descriptionprovided for the locking mechanism for rotation. The following describesa locking mechanism for tilting.

FIGS. 36 and 37 illustrate, respectively, locked and unlocked positionsof locking arms 230 of the central housing 226 of the rotation portion204. FIG. 36 illustrates a squeezed position in which locking arms 230are squeezed together at tabs 232. As shown in FIG. 37, an unlockedposition can be achieved by depressing the non-tabbed ends 234 of thelocking arms 230. FIGS. 38-39 illustrate opposing prospective views ofone of the locking arms 230. One of the locking arms 230 can be a mirrorimage of the other of the locking arms 230.

The locking arms 230 are provided on opposing sides of the tilt portion202, as shown in FIG. 40, so as to pivot or rotate about a rotationalengagement between the locking arms 230 and the tilt portion 202.Adverting back to FIGS. 36 and 37, it can be seen here that the centralhousing 226 of the rotation portion 204 covers the rotational engagementbetween the locking arms 230 and the tilt portion 202 when the centralhousing and the rotation portion 204 are assembled together.

FIGS. 40-41 illustrate an unlocked position between a locking arm 230and the tilt portion 202. Similar to the cam 210, the locking arm 230includes a plurality of teeth 236. The tilt portion also includes aplurality of teeth 238 that are arranged to engage and create a lockingengagement with the teeth 236 of the locking arm 230. FIGS. 42-43illustrate a locked engagement.

FIGS. 44 and 45 illustrate top and bottom perspective views of the tiltportion 202. The tilt portion includes a plurality of markings 238 fortilt alignment measurements, as well as a rotational axis 240 that isarranged to rest within a corresponding recess 242 provided in thecentral housing 226, as shown in FIG. 29.

FIG. 45 illustrates a fiducial marker 244 that is included in the tiltportion 202. This fiducial marker 244 can be arranged coaxially with thethrough hole 208. The fiducial marker 244 can be utilized via MRIimaging for trajectory verification. The fiducial marker 244 can includea fluid that is MRI visible. A diameter of the fiducial marker can beabout 5.25 mm.

Adverting back to FIG. 20, the rotation portion 204 can include firstand second alignment lines 246. The alignment markings 224 can be spacedevery 10° and can be arranged so as to coincide with the first andsecond alignment lines 246 with respect to determining a rotationalposition of the rotation portion 204 and the tilt portion 202. The firstand second alignment lines 246 can also coincide with tilt markings 248.These tilt markings 248 can be staggered and spaced several degreesapart, with respect to left and right sides, to limit the number ofmarkings on the tilt portion 202. The tilt markings 248 can be spacedapart by 1°, 2°, 5°, 10°, 20°, 30° or 1-30°. Similarly, the first andsecond alignment lines 246 can be staggered by several degrees in therotation and tilt directions to limit a number of alignment lines on thevarious components. The lines 246 can be spaced apart by 1°, 2°, 5°,10°, 20°, 30° or 1-30°.

The legs 206 can resemble the legs described in US 2010/0042111.However, modifications can be made. FIGS. 46-47 illustrate a foot 250 ofa leg 206. The foot 250 and the leg 206 can be coupled together by aball-socket joint 252 that allows for both rotational and tilt motiontherebetween. The joint 252 can include a spherical structure thatextends from either one of the legs 206 or the foot 250. In theimplementation shown, the spherical shape extends from the leg 206 andis coupled to the foot 250 by a foot cap 254. The foot cap 254 can beremoved from the foot 250 using a twist bayonet-type locking mechanism.An unlocked position is shown in FIG. 46, whereas a locked position isshown in FIG. 47. In the locked position, relative movement between theleg 206 (the joint 252) and the foot 250 is impeded by a frictionalengagement, whereas the frictional engagement is lessened and/or removedoutright in the unlocked position of FIG. 46. The cutouts 268 have anangled edge which assists in keeping the foot cap 254 in the lockedposition via the protrusion 256. In the locked position, the protrusion256 is held at a first position within the cutout 268. The foot cap 254is moved to an unlocked position by twisting the foot cap 254 to causethe protrusion 256 to progress an inclined or angled edge 270 of thecutout 268 until the protrusion traversed the angled edge 270, and thefoot cap 254 can decoupled from the protrusion 256.

FIG. 48 illustrates the foot 250 as being completely disconnected fromthe leg 206 and the foot cap 254. As shown herein, the foot 250 includesprotrusions 256 that are inserted into respective cutouts 268 of thefoot cap 254, as well as a protrusion 258 that is arranged to maintainat least a loose coupling between the foot cap 254 and the foot 250,when the foot cap 254 is in an unlocked position. The foot 250 can alsoinclude a plurality of spikes 260 about 0.1-1.5 mm, such as 0.4, 0.5,0.6, 0.8 or 1.0 mm in length, which may be made from a titaniummaterial. The titanium material is strong and sharp and will not bendwhen being pressed into the skull. Further, a straight profile of thespikes 260 reduces the resistance when being pressed into the scalp. Thespikes 260 can be molded into the foot 250, which is also made ofplastic or titanium. Prior to installation, as shown in FIG. 49, thespikes 260 can be covered by a spike plate 262. FIG. 50 illustrates thespike plate 262 by itself, and FIG. 51 illustrates a titanium spike 260by itself. In FIG. 51, the titanium spike 260 is shown as including anail portion 264 and a grooved portion 266. Several grooves are providedto create a rigid and reliable connection between the foot 250, whichcan be a molded plastic, and the titanium spike 260.

FIGS. 52-54 illustrate various views of the foot cap 254 having thecutouts 268. FIGS. 52 and 54 illustrate respective bottom and topperspective views of the foot cap 254, and FIG. 53 illustrates a sideview of a foot cap 254. As shown in FIG. 53, the cutouts 268 include theangled edge 270 to promote a locked position with the protrusions 256.

Although not shown, the spike plate 262 can include holes and/or groovesso that a sterilization gas can contact the titanium spikes, which areintended to be inserted into a patient's skull. Such a sterilization gascan be, for example, ethylene oxide. Further, leg numbers can be addedto the frame 214 and/or the retaining ring 220 such that identificationof a particular leg of the miniframe can be easily identified from alook-down position. Further, the spikes 260 can be varied in lengthbased on a particular placement, and the foot 250 can be increased insize to create a larger footprint to extend around areas where screwsand/or spikes cannot be attached to a patient's skull.

Although a preferential order of alignment of the various components caninclude positioning and securing the legs 206, then rotating therotation portion 204, and then adjusting the tilt portion 202,orientation of the miniframe 200 can be made following a different orderof steps, without diverting from the steps of this disclosure. Forinstance, fiducial markers can be attached to the patient's skull to mapa three-dimensional surface profile of the patient's skull, and the tiltand rotation and leg 206 lengths of the miniframe 200 can be calculatedprior to mounting the miniframe 200 to the patient's skull. Once thecalculations are verified, verification of the calculations beingperformed by modeling a rendered miniframe 200 or placing an actualminiframe 200 having the calculated settings applied thereto to thepatient's skull either in the physical space or in the rendered space.Once verified, then the miniframe can be attached via spikes or screwsto the patient's skull, and the trajectory can then be verified throughMRI scanning or optical imaging.

In light of the above, it should be appreciated that the independentlyrotating and tilting portions of the miniframe can simplify adjustments,wherein a tilt-point (i.e., the tilt portion 202) is provided so as tobe displaced from a patient's skull. The tilting and rotational portionscan also be independently locked with non-friction (i.e., non-pressurebased) locks. That is, teeth locks can be independently provided foreach of the tilting and rotational portions. Pressure/friction-basedlocks/holders can be utilized to secure a probe and/or a probe driver orother instrument engaged with the miniframe via the tilting portion.

The miniframe can be a single-use, disposable component, in that aminiframe is used per patient. A single miniframe is usable withmultiple probes, trajectories and procedures in succession for thepatient.

The miniframe provides full rotational freedom of the rotating part andthe tilt portion, and a wide range of tilt angles for the tilt portion.The locking mechanisms can be easily released and reset. Thus, atrajectory can be modified and re-locked in real-time based on real-timeimage data or to set a next trajectory in a treatment procedure.

In planning, setting, registering or modifying a trajectory, anMRI-visible portion of the miniframe (such as the fiducial marker 244)can be used, via MRI imaging, to verify a position of the miniframe,especially with respect to a target tissue or intended trajectory.Moreover, a further MRI-visible portion, such as a fluid filled tube,can be placed in the through hole 208 or in a device that is insertedinto the through hole 208 to provide an MRI-visible indication oftrajectory of the miniframe.

The miniframe provides a tilt/pivot point that is in a different radialposition than an entry point, with respect to a spherical coordinatesystem.

III. Probe Driver

An exemplary probe driver that can be utilized in accordance with thevarious aspects presented in this disclosure is described in U.S. Ser.No. 12/540,558, filed Aug. 13, 2009, published as US 2010/0042112, theentirety of which is incorporated herein by reference.

An exemplary probe driver is shown in FIG. 5. FIG. 5 illustrates theprobe driver as including a commander, connected to a follower byumbilicals, and a position feedback plug connected to a potentiometerassembly of the follower. The position feedback plug is plugged into aninterface platform and the umbilicals include sheathed wires thatindependently control rotational and longitudinal motion of a probe orother longitudinal member held by the follower. Independent control ofthe rotational and longitudinal motion is provided by rotating arespective one of the knobs or dials provided at either side of thecommander. An exemplary structure for the corresponding mechanisms thatprovide the rotational and longitudinal motion is described and shown inUS 2010/0042112, the entirety of which is incorporated herein byreference.

FIG. 55 illustrates a commander 300 of an exemplary probe driver. Thecommander 300 includes opposing knobs or dials 302 and 304 (herein knobs302 and 304). These knobs 302 and 304 independently control longitudinaland rotational motion, e.g., in a manner that coincides with thatdescribed in the exemplary structure of US 2010/0042112. The commander300 is arranged to be mounted to an interface platform body, as shown inFIG. 55, via corresponding holes and mounting posts.

The knobs 302 and 304 each include gear teeth that are structured to beengaged with corresponding gear teeth 306 and 308 of the interfaceplatform. The interface platform includes motors to respectively rotatethe gear teeth 306 and 308 in response to corresponding instructions(data) received from a workstation in an MRI control room (see FIG. 1).When the commander 300 is coupled to the interface platform, rotation ofthe gear teeth 306 and/or 308 is translated to the gear teeth of theknobs 302 and/or 304, which results in independent control of therotational and longitudinal motion.

FIG. 56 schematically illustrates either of the knobs 302 and 304engaged with the interface platform via an engagement between the teeth310 of the knobs 302 and 304 and the teeth 306 and 308 of the interfaceplatform. Either or both of the knobs 302 and 304 include a contouredsurface 312 for manual manipulation thereof, as well as a bolt orfastener 314 that secures the knobs 302 and 304 to internal mechanismsof the commander 300.

Other engagements are also possible, including toothless frictionrollers. With any type of engagement, a rotational motion originatingfrom a workstation, that causes the gear teeth 306 and/or 308 (or otherinterface platform rotational driving mechanism) to rotate, causes theknobs 302 and/or 304 to rotate. Consequently, rotational and/orlongitudinal movements via the follower are enacted. These movements arethen tracked via a potentiometer assembly in the follower, and afeedback signal is provided to the interface platform. Consequently, aworkstation receives electronic positional feedback and is able toverify that an instructed command resulted in an intended rotationaland/or longitudinal alignment, and can responsively output furthercommands to the commander to achieve an intended alignment, should theinitial command not result in a particular or intended position. Theworkstation monitors such unintended alignments to determine whether anamount of slippage in the various mechanisms is above a certaintolerance, and displays a warning error so that the mechanisms can bevisually inspected to ensure proper setup and functioning.

In conjunction with electronic control provided via the workstation, aclinician at the workstation, which is coupled to the probe driver viathe electronics rack and the interface platform, is provided with anautomated drive means that is spaced apart from the MRI (that is,outside of the bore of the MRI), but is coupled to a flexibleMRI-compatible umbilical, which is in turn coupled to a motorless drivesystem positioned within the bore of the MRI and/or a head coilpositioned around the head of a patient. Actuation of the drive meanscan therefore be accomplished by a clinician who is not in the MRI room,but is rather in a control room, such as an MRI Control Room, andcontrol of the motorless drive system can be provided while the MRI isoperating and images are being collected. Further, continuous,uninterrupted control of neural laser ablation (or other treatmentdepending on the probe structure) is possible when the probe in userequires repositioning. That is, in a multi-step treatment, e.g., amulti-step ablation, operation of the MRI can be continuous while aprobe position is changed in either or both of rotational andlongitudinal directions.

In various implementations the probe driver provides full remote controlto an operator that is located either: (1) in the proximity of the MRIand an interface platform that the probe driver is connected to, or (2)in a remote room, such as a control room, at a workstation, where theworkstation sends positioning signals to the interface platform toactuate corresponding movements by the commander. Full remote control ofthe probe drive is thus provided, which reduces procedure time.

Further, the probe driver in this illustrated implementation canprovide, at a minimum, a translation of 20-80 mm, 30-70 mm, 40-60 mm or40 mm, with a maximum translation of 60 mm, 80 mm, 100 mm, 120 mm or60-150 mm or more. The probe driver in this illustrated implementationcan also provide, at a minimum, a rotation of 300°-340°, with a maximumrotation of 350°, 359°, 360°, 540°, 720° or more or of any anglestherebetween.

IV. Probe

A plurality of different probes can be utilized in accordance with thevarious aspects presented in this disclosure.

Exemplary probes are described in: U.S. Pat. No. 8,256,430, filed Dec.17, 2007; U.S. Pat. No. 7,691,100, filed Aug. 25, 2006; U.S. Pat. No.7,344,529, filed Nov. 5, 2003; U.S. Pat. No. 7,167,741, filed Dec. 14,2001; PCT/CA01/00905, filed Jun. 15, 2001, published as WO 2001/095821;U.S. 61/728,068, filed Nov. 19, 2012; and U.S. 61/664,791, filed Jun.27, 2012. These documents are incorporated herein in their entireties.

A. Side-Fire Probe

FIG. 57 illustrates an exemplary side-fire probe tip 400 (hereinsometimes referred to as merely a probe 400). Probe 400 includes acooling tube 402 and thermocouple 404. As shown in FIG. 3, thesecomponents are coupled to corresponding probe connectors that aresecured to the interface platform, as further shown in FIGS. 10 and 14.The probe 400 also includes an optical fiber 406 as an active element.The cooling tube 402, the thermocouple 404 and the optical fiber 406 areenclosed in a capsule 408. In one implementation, the capsule 408 is asapphire capsule. However, other materials can be used, includingquartz. Further, when a non-laser probe or a non-light-based probe isutilized, a material suitable for ultrasound or radio frequencytransmission can be used, and such a material can be the same as thatused for the cannula. Otherwise, other crystal structures or glass-typestructures can be utilized that effectively transmits light, withoutallowing for an effective amount of reflected light, when a laser probeor other light-based probe is utilized. Further, such materials caninclude coatings and films, such as optical films.

The optical fiber 406 includes a sheathed portion and an unsheathedportion 410. The unsheathed portion 410 includes a faceted end surface412, which causes energy, such as laser energy, to be directed in thedirection of arrow 414 to initiate therapy in a tissue. Therapy caninclude, for example, heating or light exposure. When heating a tissue,to control an amount of therapy or heat applied to the tissue, coolingis provided via the cooling tube 402, which outputs a cooling gas orfluid to the expansion chamber 416. The thermocouple 404 detects atemperature in the expansion chamber 416. A workstation can control anamount of cooling gas (either or both of a flow and pressure of the gas)or cooling fluid inputted into the expansion chamber 416 via the coolingtube 402 to control a temperature of the tissue via conduction throughthe capsule 408.

In one implementation the optical fiber 406 is rotatable with a rotationof the probe 400, for example, by rotating a follower of a probe driver.In another implementation, the optical fiber 406 is independentlyrotated by the follower, such that rotation of the optical fiber 406does not necessitate rotation of the capsule 408. As a result of theside-firing capability of the laser energy, a plurality of rotationallydifferent portions of the tissue can be treated with the laser energy byrotating the optical fiber 406 with or without rotating the capsule 408.Additionally, the capsule 408 can be longitudinally displaced by afollower of a probe driver to change a longitudinal position of thedirectionality of the laser energy within a tissue to be treated. Thislongitudinal movement of the capsule 408 results in movement of thecooling tube 402, the thermocouple 404, and the optical fiber 406 as onepiece.

In another implementation, the optical fiber 406 can longitudinally movewith respect to the capsule 408. Consequently, movement of the laserenergy from the optical fiber 406 in the longitudinal direction can beachieved without moving the capsule 408 or other parts thereof.

The optical fiber 406 can be referred to as a core of an optical laserfiber. A tip of the core can be polished at an angle of 38 degrees toprovide an exemplary side-fire probe.

B. Diffuse-Tip Probe

FIG. 58 illustrates a diffuse-tip probe 420 (herein sometimes referredto as merely a probe 420). The probe 420 includes some components thatare similar to that of probe 400. The probe 420 includes an opticalfiber 422 that has a sheathed portion and an unsheathed portion 424. Thesheath can be formed from a polymeric material such as nylon,ethylene-tetrafluoroethylene, polyamines, polyimides, and other plasticsknown for optical sheaths or jackets. The unsheathed portion 424includes a faceted surface 426. The faceted surface 426 results in adiffused output of energy in a side-firing direction, such as in thedirection of arrows 428.

The faceted surface 426 is an etched fuser tip, from which laser energy,for example, is delivered diffusely in an even or uneven distributionpattern into a tissue. A longitudinal length of the faceted surface 426,in a longitudinal direction, can be approximately 1, 1.4, 2, 3, 4-30 or45-60 mm. A plurality of similarly structured diffused-tip probes can beprovided with varying active lengths, where a particular active lengthcan be selected based on a particular tumor size to be treated. Anexemplary length is 6 mm or 4-7 mm.

With respect to the described examples, in general, the unsheathedportion of the optical fibers described herein includes a cladding,whereas the faceted surface(s) of the unsheathed portion do not includethe cladding. Additionally, the faceted surface(s) can be etched by, forexample, an acid treatment. In another implementation, one or morefaceted surfaces are replaced by etched surfaces, in which the generalstructure of the optical fiber is maintained, but a clad is not presentor removed, and the material of the optical fiber is etched to createone or more emission points. These emission points can be disposed alonga longitudinal axis and/or circumferentially to form a symmetric orasymmetric energy emission pattern.

The capsule 408 can be fixed to a rigid cannula 418, and the capsule 408can be made of quartz, sapphire or other such suitable materials. Therigid cannula 418 is formed of a suitable rigid MRI compatible materialsuch as plastic so that it is stiff in resistance to bending and hassufficient strength to allow a surgeon to insert the cannula into arequired location in the body of a patient. In another implementation,the rigid cannula 418 is only rigid in a torsional, rotationaldirection, and is flexible at one or more points so that it is bendable.

The cooling tube 402, the thermocouple 404 and the optical fiber can beattached by an adhesive to the cannula 418. The cooling tube is swagedat its end and projects into the capsule 408 to form a cross section ofreduced inner diameter on the order of 0.002, 0.003, 0.004, 0.003 to0.005 or 0.006 inches or values therebetween. The capsule 408 caninclude a step portion 430 that can be pressed fit and/or adhesivelysecured to the cannula 418. An outer diameter of the cannula 418 and thecapsule 408 is the same, and an inner diameter of the capsule 408 andthe cannula 418 is the same. However, the diameters can be varied.Additionally, a fiber optic thermometer, not shown, can be utilizedinstead of the thermocouple 404. The cooling tube 402 can supplypressurized carbon dioxide, for example, and the supplied fluid/gas canutilize Joule-Thomson cooling via Joule-Thomson expansion. However,cooling fluids which do not expand but rather circulate from the coolingtube 402 through a discharge duct can also be used.

A fluid supply for the cooling tube 402 originates from the electronicsrack shown in FIG. 1. The electronics rack is coupled to the interfaceplatform, which is in turn connected to the cooling tube 402 via theprobe connectors shown in FIGS. 3 and 14. Similarly, the optical fiberand the thermocouple are connected to the electronics rack. Via theelectronics rack, the workstation controls the flow rate of carbondioxide, for example, in a cooling tube 402 to generate a predeterminedpressure within the cooling tube 402, which can be varied so as to varya flow rate of the fluid through a neck portion of the cooling tube 402.As a result, a Joule-Thomson effect is achieved, where gas exiting thereduced diameter neck portion expands into the expansion chamber 416 tocool the probe in contact with the tissue and cool the tip of theoptical fiber that emits laser energy (such as the diffused tip portionprovided by the faceted surface 426). The cooling fluid can be suppliedat a normal or room temperature without cooling. The fluid is normally agas at this pressure and temperature. Fluids that are liquid can also beprovided such that they form a gas at the pressures from the expansionchamber 416, and therefore go through an adiabatic gas expansion processthrough the restricted orifice into the expansion chamber to provide thecooling effect. The restricted orifice or neck portion of the coolingtube 402 is therefore a venturi outlet and has a cross-sectional areathat is smaller than a main-body of the cooling tube 402.

The interior of the probe serves as a return duct which discharges thecooling fluid/gas/liquid. An exhaust duct area of approximately 190 to540 or 200 to 300 or 200 times larger than an orifice area of thecooling tube 402 can be achieved when considering a delivery orificediameter of an exemplary 0.004 inches, or an exemplary 0.002, 0.003,0.004, 0.003 to 0.005 or 0.006 inches or values therebetween. Cooling ofat least −20° C. to +20° C. is achieved with at least a 200:1(outlet:inlet) gas expansion ratio. This allows the gas, as it passesinto the expansion chamber, to expand as a gas, thus cooling the capsule408 and an interior thereof to a temperature in the range of at least−20° C. to +20° C. This range of temperatures has been found to besuitable in providing the required level of cooling to the surface ofthe capsule 408, so as to extract heat from the surrounding tissue atthe required rate of cooling. Variations in the temperature range areachieved by varying the pressure of the cooling gas/fluid so that in oneexample the pressure of the gas is between 700 and 850 psi and has aflow rate of 1, 2, 3, 4, 5 or 6-15 liters per minute. Other achievabletemperature ranges include −40° C. to +40° C., −35° C. to +35° C., −30°C. to +30° C., −25° C. to +25° C., −15° C. to +15° C., −10° C. to +10°C., and ranges therebetween. Other exemplary pressures of the gasinclude 600-650, 650-700, 700-750, 750-800, 800-850 and 700-900 psi.

To achieve a desired rate of cooling a probe is cooled to between 0° C.to 5° C., such as 1° C. to 3° C. or 2° C., by Joule-Thomson cooling.This temperature range is preferably maintained within an entirety ofthe probe before, throughout, and after a treatment or energy emissionof the probe.

A discharge of the cooling gas through the cannula 418 is at a pressureof approximately 25-50, 75 or 50 psi in the example described herein.Thus, the gas may be discharged through the atmosphere if the gas isinert, discharged to an extraction system, or collected for cooling andreturned if economically desirable. Cooling of the probe is necessaryfor optimum tissue penetration of the laser or heating energy. Coolingreduces tissue charring and sets localized cooling of the treatedregion. Probe cooling also protects the faceted surface or an otherwiseactive area of the optical fiber. The faceted surface 426, in thelongitudinal direction, is shorter than an internal length of thecapsule 408 so that the faceted surface 426, which defines the activelength, can be approximately centered within the expansion chamber 416,and so that no or little to no energy is delivered to the sheath of theoptical fiber. The faceted surface 426 is arranged such that it issurrounded by the cooling gas from the cooling tube 420 within theexpansion chamber 416. As a result, in practice, no condensate forms onthe faceted surface 426 that would otherwise interfere with reflectivecharacteristics.

In operation, the temperature of the expansion chamber 416 is monitoredby the thermocouple 404 so as to maintain the temperature at apredetermined level in relation to an amount of heat energy suppliedthrough the optical fiber. Pressure of the cooling gas is varied tomaintain the temperature at the predetermined set level during ahypothermic process.

FIGS. 59-66 illustrate alternative faceted surfaces or active areas fordiffused-tip type probes. In these figures, the structures can beconsidered as being drawn to scale. The structures can also beconsidered as accentuated in size so that their shape is readilyunderstood. Accordingly, in some aspects, the drawings can be consideredas schematic in nature and as not being drawn to scale. Further, aneffective/active area for laser-energy emission is shown by hash marks.In one implementation, the area of the optical fiber that is notsheathed and is not shown by hash marks includes cladding.

FIGS. 59 and 60 illustrate an implementation that includes a facetedsurface/active area 432 that ends in a clad portion that comes to a tip434. FIG. 59 is a side profile view of the faceted surface 432, whereFIG. 60 is a view in which the faceted surface 432 is facing outwards.The faceted surface 432 includes one or more edges, in section, that canform a single inclined surface, a plurality of inclined surfaces, or aplurality of stepped portions.

FIGS. 61 and 62 illustrate a plurality of side-firing points 436. FIG.61 is a side profile view of the faceted surfaces providing these points436, whereas FIG. 62 is a view in which the points 436 face outwards.The implementation shown in FIGS. 61 and 62 provide a plurality oflongitudinally displaced side-firing points. The points 436 are formedby recess, which can have an angular (as shown) or a curved (not shown)section. The points 436 can also be formed by merely etching surfaces ofthe optical fiber.

FIGS. 63 and 64 illustrate a structure that is similar to that shown inFIGS. 61 and 62. However, in FIGS. 63 and 64, the faceted surfaces arestructured differently. In particular, the faceted surfaces of FIGS. 61and 62 are a plurality of recesses 438 that form a saw tooth pattern.The difference in patterns between these two implementations varies apattern of energy output. One may be preferable over the other for aparticular tissue treatment shape or for a particular tissueshape/position.

FIGS. 65 and 66 illustrate a further modification to the saw toothpattern shown in FIGS. 63 and 64. In particular, FIGS. 65 and 66illustrate a graduated saw tooth pattern where individual recesses 440vary in size. The varying in size shown in these figures is shown asincreasing as the optical fiber approaches its end. However, othervariations are possible. In particular, a size of individual recessesincluded in an optical fiber can be varied to achieve a prescribed laserenergy output profile. Further, if merely etching is utilized, a size ofthe etching can be varied among a plurality of longitudinally spacedactive areas on the optical fiber, where a clad separates each of theactive areas.

The particular implementations shown in FIG. 61-66 include threeseparate longitudinally displaced side-firing points. However, two ormore side-firing points, such as any one of 2, 3, 4, 5, 6, 7, 8, 9 or 10or more points can be provided.

Consequently, an energy emission member is provided which includes aplurality of longitudinally displaced points of energy emission, whichcan be tuned, by either surface treatment or recesses, to achieve aprescribed side-firing profile of energy emission.

Compared to a non-diffused-tip probe (a non-DTP), a DTP can output aside-firing profile of energy that has a much larger longitudinal lengthwithin the tissue. By increasing an amount of energy of the DTP, anamount of heat generated within a larger portion the tissue can beincreased, relative to a non-DTP. Therefore, a temperature of the tissuecan be increased at a greater rate with the DTP than with the non-DTP.Further, with effective cooling by the probe, an amount of heatgenerated by a portion of the DTP can be canceled out by the cooling.Consequently, a more steady-state temperate of portions of tissuesurrounding a target area can be provided, and the portions of thetissue surrounding the target area can be prevented from cooling by aneffective amount.

The structure of the DTP provides a combination of higher energy outputand lower energy density, when compared to a non-DTP probe (such as aside-fire probe). A larger treatment area can be treated within ashorter time window, when compared to the non-DTP probe.

C. Symmetric Probe

FIGS. 67 and 68 illustrate a symmetric probe with a symmetrical opticalfiber having a curved or rounded faceted end 442. FIGS. 67 and 68illustrate different sides of the optical fiber. FIGS. 69 and 70illustrate another symmetrical optical fiber, showing different sides ofthe optical fiber, where the optical fiber has a flat faceted end 444.The ends of optical fibers shown in FIGS. 67-70 can include etching atends 442 and 444.

The symmetric probes illustrated in FIGS. 67-70 provide symmetricablation patterns, in which laser output is symmetric with respect tothe longitudinal axis of the optical fiber.

The rounded end 442 shown in FIGS. 67 and 68 can provide a spherical orpartial spherical laser light output, whereas the optical fibers shownin FIGS. 69 and 70, with the flat faceted end 444, can provide a pointoutput.

Further, the other optical fibers described above can be modified toprovide a symmetric output by providing a symmetric active area around acircumference of the optical fibers.

D. Guide Sheath

FIG. 71A illustrates an exemplary guide sheath 446. The guide sheath caninclude a capsule 448 which is made out of a material that is the sameas the capsule 408 or the cannula 418. The guide sheath 446 can includea plurality of probes 450, where each of the probes 450 includes adifferent probe tip 452. In the illustration of FIG. 71A, only one probe450 is shown for simplicity. By rotation of the guide sheath 446 and/orthe individual probes 450, treatment of a same or different tissueportion of a patient can be affected by one or more of the probes 450.Consequently, only one bore hole and guide sheath insertion isused/needed to allow for treatment of a tissue by the plurality ofprobes that are simultaneously inserted into the guide sheath 446. Theguide sheath 446 shown in FIG. 71A is straight and rigid. However, theguide sheath can also be curved to accommodate a given trajectory.Additionally, the guide sheath 446 can include one or more off-axisdelivery hole(s) 454. The off-axis delivery hole 454 allows for a probeto be extended therethrough via contact surface 456. Such a structureallows for flexibility in targeting particular tissues in the patient.

The contact surface 456 has a predefined angle, and the off-axisdelivery hole 454 is predisposed. The angles shown in FIGS. 71A and 71Bcan be considered as drawn to scale in one implementation. However, thealignment of the contact surface 456 and the hole 454 can be varied byadjusting their respective axial angles. By adjusting these angles, aplurality of possible positions of a probe 450, for insertion into atissue through the hole 454, are provided. Further, multiple holes andmultiple contact surfaces can be provided, which are displaced from eachother in a direction of the longitudinal axis of the guide sheath 446.

FIG. 71B illustrates two probes 450 a and 450 b that are simultaneouslyinserted into the guide sheath 446 and can affect treatment of a tissueindependently or at the same time. The two probes can provide either orboth asymmetrical (side-fire type probe) and symmetrical (point orspherical ablation type probe) treatment patterns. As shown in FIG. 71B,the contact surface 456 can direct a probe tip 452 a of the probe 450 athrough the hole 454. The probe tips 452 a and 452 b can be commensuratewith any of the probes, probe tips and optical fibers described herein.

The probes 450 a and 450 b can be independently or collectivelycontrolled with respect to axial/longitudinal movement and/or rotationalmovement. Further, one of the probes 450 a and 450 b can be dedicated tocooling, whereas the other of the probes 450 a and 450 b can bededicated to laser treatment. A cooling probe includes a cooling tube,temperature sensor and an expansion chamber in accordance with thedescriptions provided herein.

The cannula of the probe 450 a shown in FIG. 71B is flexible withrespect to bending, such that the surface 456 causes the probe tip 452 ato extend through the hole 454. A material for the cannula for the probe450 a can be selected such that the probe 450 a has high torsionalrigidity, and such that rotational movements of the probe 450 a areeffectively translated to the probe tip 452 a. Additionally, a meshjoint or other type of joint can be utilized in at least a portion ofthe cannula for the probe 450 a that allows for bending, but maintainstorsional rigidity.

A side-fire probe can provide an asymmetrical treatment pattern, whereasa point or spherical ablation probe can provide a symmetrical treatmentpattern. Multiple probes of either or both functions are inserted into acommon sheath. With respect to the multiple probes illustrated in FIG.71B, various exemplary sequences are available for an order oftreatment. In particular, one probe can provide a symmetrical treatmentpattern to affect a tissue, which can be followed by an asymmetricaltreatment pattern. Further, a spherical ablation can then be followed byanother probe, such as probe 450 a, by treatment via an off-axis hole ina guide sheath. This other probe can be a symmetrical, asymmetrical orother type of probe.

With reference to FIG. 71B, this other probe can be the probe 452 a,which can then be rotated. The probe tip 452 a can also be retracted,the guide sheath 446 can be rotated, and then the probe tip 452 a can beextended to continue another step of treatment. The probe tip 452 a canbe a symmetric or asymmetric probe tip.

The order of the above sequences can be altered.

The hole 454 can be provided at a tip/end of the guide sheath 446, andprobes within the guide sheath 446 can be independently rotated withrespect to the guide sheath 446. The probes can be rotated after beinginserted through the hole 454 and/or before being inserted through thehole 454. The hole 454 can also be provided at various locations toalter a deflection angle, with respect to a longitudinal axis, of aprobe inserted therethrough.

The guide sheath can be straight or designed to provide a fixed angleoff-axis delivery. The guide sheath can also be curved. Trajectories canbe planned that include multiple guide sheaths, including multiple burrholes, multiple trajectories and multiple guide sheath introductions.

E. Probe Modifications and Procedure Considerations

A family of probes can be defined as catheters which differ from oneanother with respect to one or more of the following variables:

i. A number of probes simultaneously positioned in a guide sheath,including one or more probes. With multiple probes, the probes can beprovided with group or individual axial movement and/or rotation, one ormore of the probes can be dedicated to cooling only, and probes can beindividually extended and retracted from the guide sheath.

ii. Diffuse or point emission.

iii. Symmetrical or asymmetrical emission.

iv. Axial or off-axis probe delivery.

v. Steerable head, where the probe includes a structure that can changea course or trajectory of the probe with respect to a trajectory definedby a guide sheath or other axial guiding structure.

Examples described include those relating primarily to a laser-basedprobe tip, in which thermal energy is used to affect treatment to atissue. However, other types of probes and probe tips can be utilizedwith aspects of the examples described herein. In particular, radiofrequency emitting probe tips, high-intensity focused ultrasound probetips, cryogenic probe tips, photodynamic therapy probe tips, and druginjection probe tips can be utilized independently or in conjunctionwith a light source emitting probe tip, such as the laser-based probesdescribed herein.

A varied level of ablation control is available to a user. With multipleprobes inserted into a common sheath, a workstation can independentlycontrol each probe within a sheath. Thus, each emission point of theprobes can be independently controlled to obtain an arbitrary treatmentshape of the tissue. Further, the probes can be independently rotatedand longitudinally displaced. By combining the different probes within acommon sheath, operation time can be reduced since various steps of theprocedure shown in FIGS. 17-19 do not need to be repeated. Inparticular, various aspects of trajectory planning do not need to berepeated for a number of probes inserted into a common guide sheath.

In light of the descriptions provided herein, a neural ablative laserprobe with Joule-Thomson cooling is provided. Further, a laser probewith longitudinally spaced apart emission points is provided, where theprobe is rotatable about a longitudinal axis. Additionally, theillustrated longitudinal spaced emission points in the drawings in FIGS.61-66 can be applied to other probe technologies, including radiofrequency (RF) and high-intensity focused ultrasound (HiFu)technologies. HiFu technology, in particular, provides enhanceddirection control and greater depth penetration. Further, constructiveand destructive interference can be utilized by the plurality ofdifferent longitudinal spaced emission points to fine tune a positionand depth of energy applied to a tissue.

As shown in FIG. 72, a probe tip 458 can include electronic emitters460. These electronic emitters 460 are longitudinally spaced apart,where the probe tip 458 is rotatable about its longitudinal axis. Thelongitudinally spaced apart emitters 460 are shown in a regular period.However, the spacing between the electronic emitters 460 can be variedand irregular. The electronic emitters are sonic energy emitters orradio frequency emitters. The probe tip 458 is combinable with thecapsule described herein that includes a cooling tube and athermocouple.

Rotation, intensity, duty cycle, longitudinal positioning, and coolingare controlled by the electronics rack and the workstation. A sequence,such as an algorithm or software encoding, can be executed to cause aprobe tip or a plurality of probe tips to execute a particular ablationpattern to affect a predefined treatment scheme to a target tissue area.The ablation pattern can include rotational and/or longitudinalmovements.

A probe tip 462, as shown in FIG. 73, can include two or more opticalfibers 464 and 466. Optical fiber 464 is illustrated as a diffuse-tipoptical fiber, whereas optical fiber 466 is illustrated as a side-firepoint emission optical fiber. In this case, the probe tip 462 canprovide two separate types of asymmetric ablation. The probe tip 462also includes a cooling tube and thermocouple or other sensor, in amanner consistent with the other examples, but is not shown.Additionally, other combinations of faceted surfaces or active areas canbe combined together, such that any of the laser emission examplesdescribed herein can be combined together in a singular probe tip toallow for ablation of a tissue with various types of emission patterns,without requiring a new probe to be inserted into a patient for eachablation pattern. Further, the probe tip 458 shown in FIG. 72 can beincluded with one or more of the optical fibers shown in FIG. 73.

As shown in FIG. 74, a probe 468 is illustrated. The probe 468 includesan optical fiber 470 that includes a sheath or clad 472. The sheath orclad 472 is fixed to a capsule 474. In this particular implementation,only the optical fiber 470 extends into the capsule 474. Within thecapsule 474, the sheath or clad 472 (and in some implementations, bothof a sheath and a clad) are removed from the optical fiber 470, and theoptical fiber includes a faceted surface 476. Depending on a structureof the faceted surface 476, the probe 468 can be a diffused-tip probe, aside-fire probe, and/or have a structure that coincides with thatillustrated in any of FIGS. 59-70 and 72. In the case of FIG. 72, theoptical fiber is replaced with an electrical cable and suitable emitters460.

In some implementations, the probe 468 can be utilized in the guidesheath 446, where the optical fiber 470 is flexible and allows theoptical fiber 470 to bend by contacting a surface 456 and exit through ahole 454. The probe 468 can also be utilized individually, withoutcooling. A length of the capsule 474 can be approximately 3, 4, 5, 6, 7,8, 9 or 10 mm, and a diameter of the capsule can be 0.3, 0.4, 0.5, 0.6,0.7, 0.8, 0.9, 1.0 or 0.5 to 1.0 mm. A non-treatment end of the probecan be fixed to an adapter to connect to a follower to enable rotationaland longitudinal control in accordance with the other portions of thisdisclosure. A diameter of the optical fiber 470 can be 150, 200-800,300, 400, 500, 600, 700 or 800 micrometers.

A plurality of probe lengths are provided in any of the probe examplesdescribed herein based on a degree of longitudinal travel allowed by afollower and a depth of the tissue to be treated. An appropriate probelength can be determined by the interface platform and/or theworkstation during a planning stage, or determined during a trajectoryplanning stage.

Exemplary probe lengths can be indicated on the probes with reference toa probe shaft color, in which white can indicate “extra short” having aruler reading of 113 mm, yellow can indicate “short” having a rulerreading of 134 mm, green can indicate “medium” having a ruler reading of155 mm, blue can indicate “long” having a ruler reading of 176 mm, anddark gray can indicate “extra long” having a ruler reading of 197 mm.Different model numberings can also be utilized on the probes toindicate different lengths.

Exemplary lengths of the probe structures are shown in FIGS. 75-77.These figures are drawn to scale and measurements are given inmillimeters, unless otherwise indicated. FIG. 75 illustrates thecomponents of the probe shown in FIGS. 3-4. FIGS. 76-77 illustrate thedimensions of an exemplary capsule. An exemplary probe with an outerdiameter of 3.3±0.05 mm is shown.

In exemplary implementations, the guide sheath is MRI compatible, andmay be introduced through a burr-hole that is created surgically. Asheath with at least one distal opening to be placed in a target areacorresponding to a region of interest can be utilized in oneimplementation. In another implementation, a sheath with at least oneproximal opening can be provided for the delivery of other or aplurality of devices. In some aspects, the sheath may be air-tight for aneurosurgery operation. The sheath may also include a through lumen toallow other devices to be delivered therethrough. The sheath may includea walled structure to physically or mechanically support other devicesinserted therein. A sheath may also be delivered with an introducer anda wire. A sheath in accordance with one or more of these aspects canallow for multiple accesses to a treatment site while avoiding undesiredinterruption of a meninges layer. A sheath in accordance with one ormore of these aspects can allow for an expanded treatment space throughmultiple apparatuses with minimal invasive access.

V. Head Coil and Stabilization System

An exemplary head coil and stabilization system that can be utilized inaccordance with the various aspects presented in this disclosure isdescribed in WO 2012/137179, filed Apr. 5, 2012, the entirety of whichis incorporated herein by reference.

FIG. 2 illustrates a patient inserted into a bore of an MRI. Thepatient's head is fixed to a head fixation ring by fixation pins. Thering is received in a ring mount of a platform. The platform extends, ina direction away from the bore, providing a head coil support. After aminiframe is installed onto the patient's head, and the patient's headis fixed to the head fixation ring, an MRI coil is coupled to thefixation ring and the coil support. Further, as shown in FIG. 2, thecoil support includes receiving holes for attaching the interfaceplatform thereto.

FIG. 78 illustrates a platform 500 including a plurality of handles 502.After a patient is sedated, and the trajectory planning procedure iscompleted, a miniframe and/or fixation ring is attached to the patient'shead. The fixation ring can be secured to the ring mount 504 in, e.g.,an operating room in which the trajectory planning procedure isconducted. The patient can then be wheeled to an MRI room, whereoperators/assistants can utilize the handles to move the fixated patientfrom, e.g., a wheeled operating table to an MRI table. A head coil isfixed to the fixation ring and/or the head coil support 506 in theoperating room on the operating table or in the MRI room on the MRItable. An interface platform is inserted into the receiving holes 508,which is illustrated in FIG. 6.

As shown in FIGS. 78-79, the ring mount 504 includes a channel 510, inwhich a fixation ring rests. The fixation ring is locked into the ringmount 504 via knobs 512, which are provided at distal ends of the ringmount 504. FIGS. 78-79 illustrate alternate perspective views of thering mount 504.

The ring mount 504 includes attachment mounts 514. The attachment mounts514 can be utilized in a trajectory planning stage to mount a referencearray, such as, e.g., a reference guide of an image-guided surgerysystem. In particular, a tracking instrument is attached to theattachment mounts 514 to locate the head fixation ring 516 (andtherefore the other components of the stabilization system, includingthe head coil etc.) in rendered space. A convention reference arrayutilized in image-guided surgery can be utilized with the attachmentmounts 514.

FIG. 80 illustrates a head fixation ring 516 fixed to a patient's head518. A miniframe, probe follower, and probe are attached to thepatient's head, and an interface platform is coupled to the platform 500and wired to the active components. A head coil 520 is fixed to the headfixation ring 516, and includes, generally, two halves. A first half 522has a half-cylindrical shape and is substantially continuous. A secondhalf 524 has a generally half-cylindrical shape, but includes a slot526, which extends in a longitudinal direction of the patient. A bentportion 528 of the second half 524 of the head coil 520 bends towards alongitudinal axis of the patient in the direction towards the interfaceplatform, in the direction away from the patient. As a result, acontinuous coil can be provided, which allows for a trajectory to bealigned at or near a side to forehead region of the patient's head. Inthe event that a side trajectory (i.e., entry into a side of thepatient's head) or a top-of-head trajectory is planned, a head coil thatdoes not include a bent portion, but merely includes a slot thatcoincides with a cylindrical structure, can be utilized. These varioushead coils can be interchanged with the first half 522 of the head coil520.

The first half 522 of the head coil 520 also includes a plug connector530 that is coupled to a cable 532, which is in turn connected to theMRI system. This cable 532 energizes the head coil 520 and/or transmitsdata signals. The length of the cable 532 can be adjusted to accommodatea particular arrangement of head coils and other structures providedwith the MRI.

FIG. 81 illustrates the head fixation ring 516 including a plurality,such as two, fixation posts 534. These posts 534 each include a seriesof holes, each of which can engage a fixation screw 536, which pressesportions of the patient's skull above and in front of the patient'stemples back against a backrest 538. The head fixation ring 516 includesa plurality of holes 540 that are provided to engage a locking pin (notshown) from the knobs 512. The head fixation ring 516 can rotate withinthe channel of the ring mount 504, but is rotationally locked byengaging the knobs 512 with one of the holes 540.

FIG. 82 illustrates an exemplary second half 542 of the head coil 520.The second half 542 includes a slot 526, and is suited for access in thedirection of the bold arrows shown in FIG. 82. The second half 542includes connectors 544 that provide alignment and electricalconnections with corresponding connections on the first half 522 of thehead coil 520. FIG. 83 illustrates another view of the second half 524of the head coil 520, where access to a patient's head in the directionof the bold arrows is provided. As shown herein, the second half 524also includes connectors 544.

In light of the descriptions provided herein, the head coil 520 and thehead fixation ring 516 are rotated to suit a particular trajectory, andare locked into place. The interchangeability of the second halves ofthe head coil allows for flexibility in trajectory planning, andaccommodates the physical presence of a miniframe, a follower, and aprobe. Either of the second halves 524 and 542 allow for a rotatableportal, such as the slot 526. In particular, the slot 526 is rotatableabout a longitudinal/patient axis, and can be fixed into place via thehead fixation ring 516. The slot 526 allows for side or angled points ofentry into a patient's skull. These points of entry can be referred toas radial points of entry, and the structures described herein allow forradial points of entry along an entire crown line of a patient, whilefixating the patient's head. The bent portion 528 of the second half 524provides a rotatable portal that allows midpoints between a side of apatient's head and a top of the patient's head to be accessed directly,while still maintaining continuity with respect to the electromagneticproperties of the coil.

Other coils can be attached to the head fixation ring 516 or to anothertype of ring that is fastened to the platform 500. The platform 500 canbe adjusted to adapt and connect to various different MRI tables, suchas different MRI tables provided with different MRI machines.

VI. Visualization and Control

FIG. 1 illustrates a control workstation provided in an MRI controlroom, as well as an electronics rack in an MRI equipment room. Theelectronics rack is coupled to an interface platform by variouselectronic, optical and cooling fluid cables. The electronics rack isalso connected to the control workstation by, for example, networkcabling or other data transfer cables. Although not shown, theelectronics rack and the control workstation can be coupled together bya network, such as an Ethernet network. In another implementation,electronic data cables can be routed directly from the interfaceplatform to the control workstation, without use of any interveningdevices.

A. Planning

i. Plan Register

An operator can operate the workstation to initialize software executedon the workstation to provide a control terminal and graphic userinterface for creating a plan, which defines an organization ofappropriate information for the treatment of a particular tissue. Toinitiate and create a plan, the user operates the workstation to executea graphic user interface, such as graphic user interface (GUI) 600,shown in FIG. 84. The GUI 600 includes a selectable area (hereinreferred to as an area, button or region) 602 for selecting a particularMRI system, such as a brand/model of an MRI. An area 604 is provided toinclude brief instructions and/or comments to an operator, and a startarea 606 is provided to initiate the start of a plan.

FIG. 85 illustrates a screenshot of a registration of the plan. In thisscreenshot, the GUI 600 includes an information area 608, whichindicates that all image sets are registered to a single master series.Adjustments to images and images sets can be made via the GUI 600. Forexample, a blend area 610 is provided for adjusting a blending ratio.Further, an area 612 is provided for making other adjustments to theimages, including magnification, panning, contrast, and others. Markerscan also be included in the images to identify a particular tissue ofinterest. Further, in this screen, images can be loaded from the variousdata sources, including a network storage unit or a local portablestorage unit, such as a USB drive. As shown in FIG. 85, multiple imagescan be arranged in a thumbnail view, which allows a particular thumbnailto be selected and shown in one of a plurality of larger views.

FIG. 86 illustrates registration amongst the plurality of images. Inregion 614, various selectable areas are included, includingauto-registration, registration tools and registration verification.Auto-registration performs a best-fit analysis of two anatomical datasets (e.g., images) based on predetermined thresholds within an anatomy.If the auto-registration is deemed inaccurate by an operator, or if amanual registration is desired, the rotate and pan selectable areas ofthe registration tools can be operated to adjust the registration. Theblend selectable area allows for an accuracy of the registration to bechecked by a user, by blending a selected data set into or out of viewwith the master series. This tool is used to verify the registrationaccuracy of each image set registered to the master series. Onceaccurately registered and verified by the operator, the operator canindicate that the registration has been verified by selecting the verifyregistration area of the registration verification portion. After theimages have been registered, a volume can be planned.

ii. Plan Volumes

FIG. 87 illustrates a volume planning screen of the GUI 600. In thisscreen, contours can be inputted via the selectable areas includingregion 616. With this interface, an operator can define all regions ofinterest using contour tools. Parallel contours can be drawn on anyplane. Perpendicular contours can be drawn on sagittal and coronalviews. This interface allows an operator to generate volumes or intendedtreatment areas, also known as regions of interest (ROIs), within thedata set in different pre-set colors. An ROI can be defined here usingappropriate contour tools provided by the GUI 600. For treatment of atissue, the operator creates at least one ROI over an intended treatmentarea. The planned volumes portion is accessible by selecting anappropriate selectable area, such as area 618 to select a volumes task.

FIG. 88 illustrates an interactive method of generating atwo-dimensional contour. An interactively segmented contour can beselected by selecting area 620 of the GUI 600. This outlines a desiredregion and then generates a volume from the contours. Different contoursare drawn in the sagittal or coronal views, and these contours arecomputed, by the workstation, to generate a volume.

FIG. 89 illustrates how the contour can be adjusted by using an editingcommand, such as a push command, via selectable area 622. Since anintended area for treatment of a tissue is generally not symmetrical,the push command allows for a pushing action to be implemented on thecontour shown in the various views of the GUI 600. In particular, acontour at an intended location can be created in each of variousorthogonal views. This contour may initially resemble a geometric shape,such as a circle or an oval. Then, this or other contours can be editedas required by the operator with the push tool. By operating a mouse orother input instrument at the workstation, the operator can push theboundaries of a contour with, for example, the white circle shown inFIG. 89 to achieve a desired shape. The size of the white circle can bechanged by toggling a button on the mouse to accommodate larger orsmaller manipulations. For example, while activating a left or rightclick button of a mouse, the size of the push tool can be changed byoperating a wheel of the mouse. Contour lines can also be deleted bychecking a clear all button on the GUI 600, and a shape of the push toolcan also be changed from a circle to, for example, an oval, a square ora triangle. Other geometric metric shapes can also be utilized.

After the contours have been defined in the orthogonal views, a volumecan be generated by the workstation by selecting the area 624 shown inFIG. 89. This volume, as well as any other volumes created in accordancewith the description provided herein, can be named, edited, deleted,renamed, and saved in a storage medium, such as a hard disk or portabledrive, of the workstation.

iii. Plan Trajectory

After a volume has been identified, or several volumes have beenidentified, a trajectory for affecting a treatment to the volume(s) canbe planned. Trajectory planning is shown in FIG. 90. Here, the volume isencircled in several orthogonal views of the tissue, according to asaved or accessed volume plan. A probe trajectory-coronal view, a probetrajectory-sagittal view, and a probe's eye view are shown in FIG. 90. Atrajectory 626 is planned for treating the encircled volume. Whitecircles indicate insertion and maximum depth markings for the probe.This planning is intended to define an initial trajectory while in aplanning phase. The final trajectory used for actual treatment can bemodified later, if necessary. A new trajectory is defined bymanipulating “grab-handles” (which are defined as the two white circleswithin the views). The point of deepest penetration (PDP) is defined bythe workstation as a centroid of the deepest grab-handle to the deepestpoint in the brain allowable for probe insertion. This screen can alsoprovide a 3D surface rendering, as shown in the lower right of thescreen of FIG. 90.

Once a trajectory has been defined, a save command can be issued to savethe trajectory. Once the trajectory is saved, a new trajectory can begenerated for the same volume or for another volume. The trajectoriescan be saved so as to correspond with a particular volume. Thiscorrespondence can be saved by the workstation in an association file.For example, during the treatment stage, a particular volume can beidentified, and the workstation can provide associated trajectories forthat particular volume.

The various trajectories and volumes defined in accordance with thedescriptions provided herein can be saved as a plan, as a file in theworkstation. The file can be saved to a local or remote storage device.A saved plan can then be accessed later. For example, a plan can beaccessed during a treatment planning stage, and the plan can be part ofan executed sequence by the workstation to enable a continuous processof treating a plurality of volumes or a plurality of positions by theworkstation without requiring further planning or setup input by anoperator.

B. Pre-Treatment

i. Preparation

After a plan has been generated, a patient is prepared and theappropriate components are collected for conducting a treatment. Inparticular, a miniframe and a delivery probe are acquired, in accordancewith the disclosures provided herein Various drill bits are acquired fordrilling a proper bore hole size into the patient's skull. Additionally,an image guided surgery alignment adapter is acquired. The particularimage guided surgery alignment adapter is generally specific to theparticular operating room and/or hospital and is mounted to, e.g., astabilization system affixed to the patient.

At this time, operating systems of the electronics rack and theworkstation can be verified. In particular, new medical grade carbondioxide tanks can be installed into the electronics rack to be used forcooling, and power to the workstation can be verified. The patient isanesthetized according to anesthetic requirements for the procedurebeing performed. Further, the patient can be provided with earplugs inboth ears in preparation for the MRI scanning, and a medically testedand MRI compatible temperature probe can be inserted into thenasopharynx of the patient for accurate temperature readings throughoutthe procedure.

ii. Head Fixation

Post-anesthesia, the patient's head is fixated within an MRI compatiblehead fixation device using MRI compatible fixation pins. An image guidednavigation system is registered based off of a pre-operative scan. Oncethe image guided navigation system is accurately registered, an entrypoint is defined on the anatomy and the incision plan is made. Anexemplary head fixation mechanism is described in Section V.

After the head fixation system has been successfully attached, propersterile draping is applied. Further, since a miniframe and an interfaceplatform need to operate in conjunction with the other components, careshould be taken to ensure that the sterile draping does not interferewith any such components or other components utilized in the plannedtreatment. At this time, pilot holes can also be drilled into thepatient, should the patient have a very dense/hard skull or if thepatient has a cranial plating system.

iii. Miniframe

The miniframe is then mounted to the patient. An exemplary miniframe isdescribed in Section II. At this time, the miniframe can be used as adrill guide. Otherwise, a different guide can be used as a drill guide.

Also, for each foot of the miniframe, the foot should be pressed firmlyinto the scalp at a respectively marked location until all spikes of thefeet are fully seated on the skull surface. By holding a foot in place,the screws should be engaged with a sterile screwdriver. The screwsshould be alternately advanced until all screws are fully seated. Thestability of the feet attachment should be verified before proceeding. Atemplate linkage, which maintains a predefined displacement between thefeet of the miniframe, can then be removed. The miniframe can be alignedusing the image guided navigation system. In particular, as shown inFIG. 91, an image guided navigation system pointer probe 628 is showninserted into an alignment adapter 630 of the miniframe. As such, theimage guided navigation system can visualize the trajectory into theanatomy on a pre-operative scan/screen. Once alignment is secured andthe miniframe is locked into position, the pointer probe 628 can beremoved and replaced with an appropriate drill. A depth to apredetermined target, i.e., the plan volume, can be determined via abiopsy needle or via the depth predefined in the image trajectoryplanning.

After the drilling has been completed, an MRI trajectory wand can beinserted into the miniframe. The patient can then be prepped and drapedfor insertion into the bore of the MRI.

C. Treatment

i. Scan & Register

After the patient is loaded into the bore of the MRI, and the variouscorresponding components are attached and connected, in accordance withthe other disclosures provided herein, the patient is scanned to detectthe trajectory wand placed in the miniframe. An exemplary screenshot ofan image including the trajectory wand is shown in FIG. 92 as item 632.Also shown in FIG. 92 are various orthogonal views of the patient'sskull, together with a three-dimensional rendering. Based on thesevarious views, an operator can verify an alignment of the trajectorywand 632 with the previously planned trajectory. Additionally, a newtrajectory can be created if necessary.

Once the trajectory has been aligned via the trajectory wand and savedwithin the planned trajectory section of the GUI, a detected fiducialmarker within the miniframe is defined to provide a depth setting and adirectionality for a probe within the GUI in accordance with the screenshown in FIG. 93. Fiducial markers can be auto-detected by selecting anauto-detect button 634 in the GUI. If the auto-detection does not resultin detecting the fiducial markers for the miniframe, the fiducial markercan be manually set via the region of buttons 636 shown in FIG. 93. As aresult, two circles or other markers 638 are indicated in the GUI asidentifying the miniframe. Further, since the trajectory wand may stillbe inserted into the miniframe, the trajectory wand image 632 may stillbe visible within the image, and proper alignment amongst the variouscomponents can be verified within the GUI.

ii. Define ROI and Trajectories

A previously planned plan, i.e., ROIs and trajectories, is accessed viathe workstation and loaded into the GUI. Consistent with the disclosuresprovided herein, a plan can be modified or ROIs and/or trajectories canbe added to or deleted from a plan. Data management (i.e.,saving/modification thereof) can be provided via a local storage unit ofthe workstation or via a portable storage unit (such as a USB drive thatis particular to the patient).

iii. Probe Insertion

After a region of interest has been defined and image trajectories havebeen registered in the GUI and saved to the workstation, a pre-insertionpoint is defined in the GUI for probe insertion. A manual self-test isthen conducted to verify that the system is ready for treatment. Thepre-insertion point is defined by moving a probe tip 640, as shown inFIG. 94, within the anatomy to the point that the operator wants to seethe probe upon initial insertion into the desired area. Once this probetip 640 is moved to the desired position, another manual self-test isperformed. This test is started by clicking on a corresponding startbutton of the GUI. At this time, the probe tip 640 shown in FIG. 94 is arendered probe tip, which does not correspond to a physical probe tip,at least yet. A last step in the self-test procedure is manuallyinserting in the probe. Once the probe is physically inserted into thepatient, the GUI is operated to register or match the hardware of theprobe with the probe tip rendered in the GUI.

iv. Software to Hardware Match

When scanned by the MRI, the physical probe inserted into the patient isviewed from the workstation as a probe artifact within the image. Thisprobe artifact is registered and coincides with the probe tip 640 shownin FIG. 94. Scan plane parameters can be selected to coincide with theposition of the probe inserted into the patient. Once a new image fromthese parameters is loaded into the GUI, an alignment of the probeartifact can be registered with the rendered probe by adjusting grabbars of the rendered probe to match perfectly with the alignment of theprobe artifact, as shown by grab bars 642 of FIG. 95. Once thetrajectory is perfectly aligned, a trajectory can be confirmed byselecting an appropriate box in the GUI. Additionally, as shown in FIG.95, a depth stop, linear position and rotary angle of the probe can betracked and/or set in area 644 of the GUI. The linear position androtary angle of the probe is determined by the predefined relationshipsbetween the probe, the follower and the miniframe. These predefinedrelationships are spatial relationships that are utilized in imageguided navigation systems and verified in MRI images.

v. Treatment

Once the trajectory is confirmed and the physical probe inserted intothe patient has been registered with the GUI to coincide with therendered probe image, a depth and direction of the probe is set to afirst desired location to initiate treatment. Prior to treatment, andafter registration of the patient has been completed, a real-timetransfer from the MRI is established. This real-time transfer isestablished by issuing appropriate commands via the workstation to sendimages in real-time from the MRI to the workstation. At this time, theworkstation receives real-time imagery from the MRI.

In receiving real-time images, since the actual probe position (i.e.,the physical position of the probe inside the patient) is registered inthe GUI and the workstation, the actual probe can be indicated by acolor position. As shown in FIG. 96, this colored position is a redgraphic. A target position of the probe can be rendered by a bluegraphic, as further shown in FIG. 96. These colors and indications cancoincide with the labeling and colors utilized in the probe informationarea 644 of FIG. 95. As shown in FIG. 96, target and actual longitudinalpositions and rotary angle positions can be shown by corresponding redand blue graphics.

An adjustment of a linear or rotary position of the probe can be made byselecting the corresponding portion of region 644 of FIG. 95, andentering appropriate values through, for example, a keyboard. The targetrenderings of at least FIGS. 95-97 can also be selected by a cursor ormouse input by clicking thereon, and dragging the rendering into anintended position. In response, the workstation can transmitcorresponding signals to the interface platform, which in turn canrotate corresponding knobs on a commander, and consequently affectmovement of linear and rotary positions of the probe via the follower.This can all be done in real-time, where the workstation issuescorresponding instructions and commands immediately in response to anoperator's interface with the GUI. On the other hand, an execute or OKbutton can be provided with the GUI, to delay actuation of the probe tothe intended position until the OK button is selected by the operator.Further, the GUI can include parameters indicating thresholds for linearand/or rotary travel, such that when an operator issues a command thatis outside the threshold range, a warning is provided and the probe isnot moved.

Moreover, the grabbing and repositioning of the probe can be stored as asequence, which includes a plurality of positions and alignments of theprobe, which correspond to a series of treatment positions for treatingvarious portions of the ROI. This sequence can be executed in anautomated or an assisted fashion via the workstation. In particular, inone implementation, an operator saves a sequence including a pluralityof different probe positions, and the workstation transmitscorresponding instructions to effect probe movement after predefinedtreatment levels are reached in each position. Treatment can thenproceed to a next treatment, where the operator merely supervisesprogress or maintains activation via a foot pedal, the release of whichwould pause or stop probe activation/treatment. In this case, theworkstation would effect proper probe and tissue cooling between eachrepositioning, and one or more ROIs can be treated continuously withoutinterruption.

In another implementation, the workstation calculates a minimum numberof positions or a minimum amount of time necessary to effect treatmentof the ROI(s). Here, the workstation estimates an amount of timenecessary to effect treatment of an ROI at a plurality of differentpositions, and compares the various positions with their respectiveamount of treatment times. Then, the workstation calculates acombination of positions and corresponding treatment times that resultin a shortest operation period. The resulting combination of positionsand treatment times can be displayed to the operator, either as a listof steps or in a preview. The preview can include a visual rendering ofhow the total procedure is expected to progress. Thisworkstation-calculated sequence can be verified by the operator orparticular portions of the sequence can be modified by the operator. Theworkstation-calculated sequence is performed based on an expected outputof a particular probe, and can compare different types of probes andcombinations of probes in a particular sequence. For instance, in oneimplementation, the workstation calculates steps in a sequence thatstarts with a symmetric treatment by a probe, and then calculates stepswith an asymmetric treatment by another probe.

Treatment, in accordance with the workstation-calculated (and/oroperator modified/confirmed) sequence, proceeds where the operator maymerely supervise progress or maintains activation of one or more of theprobes by, e.g., a foot pedal (the release of which would pause or stopprobe activation/treatment). In this case, the workstation can effectproper probe and tissue cooling between each repositioning, and one ormore ROIs can be treated continuously without interruption.

Linear and rotary travel (e.g., repositioning) of the probe is conductedwhile the MRI is in operation, and an operator is not present in the MRIscan room. Parameters are entered into the GUI or accessed by theworkstation for a scan plane for a thermometry sequence prior toinitiating a thermometry scan. At least FIGS. 96 and 97 illustrateexemplary scan planes 646, and an exemplary view of these scan planes646. These scan planes are continuously scanned in sequence by the MRIand sent to the workstation in real-time. Lower images 648 and 650 ofFIG. 97 are also imaged in sequence and sent to the workstation inreal-time.

When the MRI images begin arriving from the MRI, an initialization phaseof the workstation and GUI computes a noise mask and allows forreference point selection. The GUI receives data from the MRI andupdates itself with a solid colored overlay indicating pixels that are apart of the mask, as shown in FIG. 97. The mask, in one implementation,is a circular region of six centimeters in diameter, which surrounds theprobe and which represents a sub region of the MRI images beingacquired. Any data, for thermometry purposes, outside of this region isignored. The MRI data within the mask is analyzed for each measurement.Pixel locations which show excessive phase noise will not be used fortemperature measurement and are cleared or rendered transparent in themask overlay. These are referred to as masked pixels. An example isshown in FIG. 97.

As MRI acquisition continues, the operator selects a minimum of 8reference points surrounding the treatment area within each view.Reference point selection is shown by example in FIG. 98. More or lessreference points can be selected, such as 1, 2, 3, 4, 5, 6, 7, 9, 10 ormore. However, 8 reference points is an exemplary suitable number.Further, the workstation can auto-select reference points, which arethen confirmed by an operator. The workstation auto-selects referencepoints by selecting a plurality of points that are separated from eachother, the ROI and/or masked pixels by pre-defined thresholds. Theoperator can also adjust reference points after the workstationauto-selects the reference points. The reference points indicate regionsof the brain that are not intended to be heated, and are utilized inestablishing a baseline temperature. In addition to the referencepoints, a minimum of eight measurements is acquired before an operatorproceeds to temperature and thermal dosage or damage monitoring.

Once the reference points have been selected and a sufficient number ofMRI measurements (e.g., eight) have been acquired, treatment monitoringcan start by selecting a start temperature monitoring button 652 of theGUI, as shown in FIG. 98. Prior to proceeding with treatment, a currentbody temperature of the patient is entered into the workstation via theGUI, as well as a current probe temperature. The current probetemperature is retrievable via the workstation through a thermocoupleconnection within the capsule of the probe, which is coupled to theworkstation via the interface platform, the electronics rack, andappropriate wiring connected to the workstation.

After inputting a baseline temperature, the color overlay of the maskedregion can be changed to a corresponding color on the color temperaturemap. FIG. 99 illustrates the mask region as a color which corresponds toa 37° C. baseline temperature. Other baseline temperatures within arange of 36-38° C. can also be utilized. This color can be green. Atthis time, probe cooling commences, which can cause the pixels in thevicinity of the probe to begin to shift from green into a blue region,indicating the tissue is being cooled. This verifies that the cooling inthe probe is operating under normal conditions. An operator can stop theprocedure to inspect and verify equipment if cooling does not appear tobe operating as intended. Further, the workstation can detect an errorand output a warning or discontinue treatment if a calculated amount ofcooling does not result in an intended detected cooling within the ROI.

As illustrated in FIG. 99, an interface 654 within the GUI can beselected to change a mode of the probe from a standby mode to a readymode, in which a foot pedal attached to the workstation is active toactuate a laser of the probe when the mode is switched to ready. If thestandby mode is active, then the foot pedal does not control laseroutput or any probe activation. If probe cooling is not operating withinset conditions or another problem is detected, then the GUI and theworkstation inhibits an operator's selection of the ready mode for theprobe. Lazing commences upon verification by the workstation and the GUIthat settings are appropriate and conditions are within thepredetermined thresholds. As illustrated in FIG. 100, treatment resultsin the GUI are shown by the GUI creating an isoline or contour line 656,which indicates a specified threshold of thermal dosage. The isoline orcontour line 656 is illustrated contemporaneously, in real-time, invarious views, including several (e.g., three) axial planar views, acoronal view and a sagittal view. The GUI and the workstation can halttreatment by the probe when the isoline or contour 656 coincides with aboundary of the region of interest that was planned in the trajectoryand volume planning procedures, or when the isoline or the contour 656satisfies a predetermined step within a sequence. Once the probe isstopped, the workstation and GUI can cool the ROI back down to thebaseline temperature, initiate rotation and/or longitudinalrepositioning of the probe and commence treatment at a different portionof the tissue. This procedure can be repeated until a plan volume hasbeen detected as being treated to a sufficient level, by means of manualoperation, a semi-automated operation or an automated operation.

During the entire procedure discussed above, the operator maintainsactivation of the foot pedal. Release of the foot pedal stops or pausestreatment. The treatment can be resumed upon reactivation of the pedal.

The various treatment trajectories for treating one or more volumes arestored in a workstation as individual sequences, which can be executedby the workstation automatically, without specifically requiringoperator input to proceed from one sequence to a next sequence, or fromone part of a sequence to a next sequence. A changeover betweensequences or portions thereof can include at least one of rotationalalignment change, longitudinal position change, laser fiber selection,probe tip selection, energy output, and duty cycle of energy output. Inparticular, when more than one probe is utilized contemporaneously,varying the probes in accordance with Section IV can be utilized inthese sequences, and can be interchanged continuously withoutinterruption of the operation of the MRI or the real time transfer ofdata from the MRI to the workstation.

vi. Noise Masking, Reference Points and Thermal Damage Monitoring

Further aspects of selecting reference points, masking noise andmonitoring thermal damage are described herein.

Aspects of this disclosure encompass a system, method, devices, circuitsand algorithms for monitoring the treatment of tissues, such as tumors,that include a process or algorithm for correcting incoming MRI data inorder to compute accurate changes in temperature over time. MRI systemssuffer from “phase drift,” which may appear as a cyclical fluctuation of“phase data” that would otherwise remain constant if no other factorswere present to influence the phase data. Factors that may influencephase data and cause such fluctuation may include, for example, tissueheating or motion. The selection of “reference points” may be used tocompensate for phase drift in order to provide accurate temperature andthermal damage values to a user.

Magnetic resonance data includes complex numbers where both a magnitudeand phase component exists. The magnitude data may be used to illustratethe “magnitude image,” the most common data form used to visualize MRdata. The magnitude image may provide, for example, a typical grayscaleimage of the brain showing contrast between different structures. Thesecond set of data that is acquired is known as “phase data,” which isrepresentative of a phase of the image being displayed. Most MRIapplications do not have a use for phase data, and merely discard thistype of data. However, certain applications, such as phase contrastangiography, MR elastography and the temperature monitoring applicationdescribed herein, may utilize the phase data. One reason for its valueis that temperature is sensitive to the water proton chemical shiftwhich is determined by the proton resonant frequency. This can bequantified from the phase component of the MR complex data.

Each pixel in a phase image has a value, particularly, an angleexpressed in radians. Generally speaking, as long as the temperature ofthe tissue being monitored remains substantially constant, the phasevalues associated with the tissue should also remain substantiallyconstant. For example, if an image of the brain is viewed every fewseconds, such as 3, 4, 5, 6, 7, 9, 10 or more seconds (such as 8) for 2,3, 4, 5, 6, 7, 8, 9, 10 or more minutes (such as 5), and then a specificpixel in the image is selected and plotted over time, ideally the phasenumber value for the selected pixel should be the same throughout theentire duration so long as the temperature remained substantiallyconstant. Furthermore, if the temperature of the brain was raised orlowered, the phase number value should also be adjusted accordingly inresponse to the temperature change. Temperature is inverselyproportional to phase change. For example, if the temperature of thebrain was lowered, then there would be a corresponding increase in thephase number value, and vice versa.

One problem addressed herein results from the fact that MRI systems arenot perfect. Such systems actually force a natural fluctuation of phaseover time due to fluctuations in the magnetic field. Therefore, evenwhen no heating is being applied to the tissue, the phase value of aselected point on an image may fluctuate over a period of time. Forinstance, the graph of phase values over time may appear sinusoidal.This type of fluctuation is problematic for temperature mapping becauseif the system does not correct for the fluctuation, the user mayincorrectly think that the temperature is increasing or decreasing whenin actuality it is substantially constant.

For example, until heat is applied to a brain during a treatmentprocedure, the brain tissue should remain at a baseline temperature ofTherefore, when phase values are plotted over time, the fact that thephase value fluctuates may mean that there is, for example, a drift inthe magnet in the MRI. Workstations are useful for tracking this drift.As will be explained in further detail to follow, reference points maybe selected in tissue areas that a user knows will remain at thebaseline temperature prior to any heat treatment. Thus, by looking atthe pattern of the drift in the reference points, the workstation or anMRI control workstation extrapolates the drift pattern to all of theareas in the image in order to compensate subsequently received images.As a result, the phase drift can be accounted for (as a constant) andremoved so that any fluctuation that an operator observes is actuallyrelated to temperature, and not extraneous factors.

In one example, eight reference points may be selected within each of aplurality of predefined treatment slices of brain tissue and used tocompensate for phase drift during the treatment. These reference pointspreferably reside within native brain tissue but are far enough awayfrom the position of a treatment probe such that the tissue surroundingthe points will not experience any substantial heating. Preferably,treatment should not be allowed to commence until the reference pointsare selected and confirmed by the operator. In one exemplary process,five of the eight reference points may be the “primary” points that areinitially used in a masking phase, while the remaining three referencepoints may be used as “buffers” in case some of the primary points aredropped due to poor signal quality as the MR acquisition continues.

In one example, the user may select the reference points in a generallycircular pattern surrounding the targeted treatment area. Selectingreference points surrounding the treatment area may provide asubstantially uniform correction around the treatment area.

A two stage noise masking phase can be used to assist an operator inselecting reference points. In particular, when MRI thermometry data(both phase and magnitude) is validated and accepted by the workstation,a mask may be computed to hide those pixels which are considered to be“noisy.” Until the operator selects to proceed in the workflow to viewtemperature data, the MRI raw data may be shown as a binary image ofpixels that pass the noise masking stage and those that do not pass thenoise masking stage. For example, the pixels that pass the noise maskingstage may be made opaque, while the pixels that do not pass the noisemasking stage may be made transparent. Other methods of distinguishingthe pixels that pass the noise masking stage from those that do not passthe noise masking stage are also possible.

FIG. 101 illustrates a sequence of processes performed via operatorinteraction and by data processing by, e.g., a workstation. The sequenceis set forth in three stages in a time-wise sequence based on an MRmeasurement number. This sequence is exemplary and includes variouscomputations performed by the workstation.

With reference to FIG. 101, the first stage of noise masking (Stage 1)may simply analyze the quality of the incoming phase data, applying athreshold to formulate a masked image. During this process, the operatormay select reference points in each of a plurality of views. Points thatdo not fall within the noise mask may be deleted. Once the minimumnumber of reference points has been selected, the process may thencontinue to a Stage 2 noise mask to compute a phase drift compensatedtemperature difference. Stage 1 may be immediately skipped if thereference points already exist prior to MRI data arriving.

In Stage 2, the reference points selected in Stage 1 may be “validated.”The reference points are used to compute a temperature difference atevery location within the Stage 1 masked region. A temperature thresholdcan then be applied. Pixels whose temperature difference exceeds thethreshold can be removed or masked, indicating to the operator thestability of the temperature mapping in the treatment area prior totreatment. The operator can continue to select additional referencepoints or delete existing reference points in order to produce a stabletemperature map.

More particularly, two parallel actions are occurring as soon as the MRIsystem begins to take measurements. First, the operator may beginselecting reference points in the Stage 1 noise masking process in orderto begin the reference point correction sequence. However, parallel tothe Stage 1 noise masking process an optional “filtering” sequence ofsteps that filters out noisy points may be performed. In particular, thefiltering sequence may begin by generating a default mask wherein all ofthe overlay pixels are opaque. The system may be designed such that themasked raw phase data may be displayed, for example, so that opaquepixels represent stable phase locations. Thus, at the most basic levelthe filtering sequence may involve comparing a first image to a secondimage and masking the pixels when unreliable data exceeds somethreshold.

Within Stage 1, the operator begins selecting reference points based onthe masked phase data resulting from the filtering sequence previouslydescribed. As briefly mentioned above, reference points are points on anMRI image that may be selected by the operator, such as by pointing and“clicking” a mouse cursor at a desired image location. For example, whenan MRI system is running it typically may send data about every eightseconds updating the image. In overlaying the MRI image there may beanother image that may ultimately become the temperature mask. Thetemperature mask may be made transparent or opaque through the use of atransparency control. Within the overlay, the operator selects pointsthat are sufficiently far from the area that will be heated duringtreatment. These points are the reference points, and they all shouldfall within the brain.

The reference points are indicators of image or phase drift in the MRI.Because a certain amount of image or phase drift occurs naturally, oncethis natural image or phase drift in the MRI is determined, all of thesubsequent phase data for the image may be compensated. The referencepoints may be selected either subjectively by the operator orautomatically by reference point selection software. Whether theselection is performed manually or automatically, it will involvenumerous factors including determining the location of the brain,segmenting the brain from the skull and other anatomical parts, and thelike. If the minimum number of reference points has been selected, thenthe operator is free to move on to Stage 2.

Any number of reference points may be used in accordance with thedescriptions provided herein. A single reference point may provide onlya single point correction and a substantially planar fit providing asingle correction value to all pixels within the image. Two or threereference points can provide a planar fit which may not describe thevariable phase drift in the image correctly. Thus, when a planar fit isused, there is no “averaging” component. However, with more referencepoints, the points can be extrapolated to the entire image, providingfor a polynomial surface fit in 3-D space. Thus, using a polynomial fitthrough the selected points is preferable because it allows for suitablecorrection throughout the entire image. In some implementations, thepolynomial fit is superior to a planar fit generated by 1, 2 or 3reference points. Fitting a polynomial surface to the selected pointscan create a correction throughout the entire treatment area withoutactually having to pick points at every location.

Further, although as few as one reference point may be sufficient for abasic planar fit, a larger number may be preferable because the operatormay unintentionally pick one or more “unusable” points. This can occurwhen the signal intensity at the reference point location drops too lowindicating poor signal and thus an unreliable phase value. Althougheight reference points are described, any number of reference pointshaving any number of extra “buffers” may be used without departing fromthe intended scope of the descriptions provided herein.

Once the minimum number of reference points is selected in Stage 1, theprocess continues to Stage 2 where the reference points may be used tocorrect for the phase drift. Until the operator transitions to the Stage3 temperature monitoring stage, the operator remains in the maskingstage and temperature is not yet being shown. In particular, during thismasking stage the system assumes that the brain tissue is at a stablebaseline temperature. As a result, all of the pixels displayed in thetreatment area on the screen should be at approximately the same,constant temperature. The temperature of each pixel is computed andcompared against a threshold to filter those regions where excessivetemperature changes are occurring based on the currently selectedreference points. Thus, the operator should be careful so as to selectthe reference points in a substantially homogenous brain tissue becausetoo many pixels can be masked out due to reference point locations tocorrect for drift.

The result of the Stage 2 computations may be a phase map comprising apolynomial surface. More particularly, when computing the polynomialsurface in accordance with the descriptions provided herein, thealgorithm should include each of the reference points selected by theoperator. The algorithm then functions to create a “surface” thatrepresents the “best fit” through all of the selected points, oralternatively close to all of the selected points. As will beappreciated by those skilled in the art, when four or more referencepoints are selected, a polynomial surface fit should be used because itmay be mathematically impossible to fit a planar surface through fourreference points. Utilizing a polynomial surface fit is preferable whenMRI phase drift is not linear. In one example, there may be slightlymore phase drift at the top of the brain and slightly less phase driftat the bottom of the brain. Thus, the correction across the entire imagepreferably utilizes a polynomial fit rather than a planar fit.

After the corrected phase has been computed, the method proceeds tocompute a drift compensated phase difference based upon the currentcorrected phase and a baseline phase that is stored in memory, such asan electronic memory of the workstation. Next, the drift compensatedphase difference is then multiplied by a constant (a PRF factor), whichgives us a temperature change in degrees Celsius. The baselinetemperature is added to the temperature change to arrive at a currentabsolute temperature value. The baseline temperature may generally beabout 37° C., which is the “normal” temperature of brain tissue prior toany heating or cooling. Other temperatures can be set, including 35° C.,36° C., 38° C., 39° C. or any fractional temperatures therebetween.

In Stage 2, temperature is not yet being displayed, but rather isrendered just as a mask. Therefore, what is being displayed in Stage 2are pixels representing computed temperatures that fall within apredefined tolerance. If the computed temperatures fall within thetolerance, then the corresponding pixels are not masked out. However, ifa computed temperature change is outside of the tolerance, then thecorresponding pixel is masked out. This step in the process may beperformed to illustrate how stable the data is so that prior to actuallytransitioning to the treatment mode (Stage 3), the operator mayvisualize the overlay mask on the image. If the operator observes thattoo many pixels have dropped out, then this serves as an indication thatthere may be a problem with the phase MRI. For instance, the MRI may notbe functioning properly or there may be something wrong with theacquisition of the data that is creating too much variation in the phasedata, thereby indicating that the temperature changes are really notrepresentative of what is actually occurring.

As long as large numbers of pixels are not dropping out, everythingappears stable to the operator and/or the workstation through monitoringof the data, and the predefined minimum number of reference pointsremain available, the operator may provide instructions to proceed tothe Stage 3 temperature display and treatment mode. However, if too manypixels have dropped out and/or the predefined minimum number ofreference points is not available, then additional reference pointsshould be selected prior to proceeding to Stage 3. The workstation caninhibit the operator from proceeding until further reference points areselected. Moreover, the workstation can select reference points oridentify reference points for the operator, which the operator canconfirm.

Once Stage 3 is entered, the operator may initially be required to enterthe appropriate baseline temperature, such as 37° C., for the braintissue in the illustrated example. Since all of the required referencepoints have been collected prior to proceeding to Stage 3, there is noneed to select additional reference points. The selection can be lockedby the workstation.

In Stage 3, the actual tissue temperature is now displayed instead ofmerely the mask. Thus, in the illustrated example, Stage 3 includes thecomputation of thermal damage. That is, a real temperature is actuallybeing computed and retained in Stage 3, and is not used as a mask. Inone exemplary implementation, the thermal damage or “dose” may becomputed using an Arrhenius-type relationship between time and tissuetemperature. This allows the operator to view temperature maps of thebrain tissue illustrating predictive damage that the software hascalculated based on the sequencing of MRI data while providing therequired treatment.

Also in Stage 3, a corrected phase is calculated as per Stage 2. A driftcompensated phase difference is calculated by subtracting a baselinephase from the corrected phase. A current absolute temperature iscalculated by adding a baseline temperature to a multiplication of thePRF factor and the drift compensated phase difference.

Thermal damage can be computed by a piecewise integration method. Onemethod is to calculate an equivalent amount of time “t” (in minutes,hours or seconds) a tissue has been held at a specified temperature “T”,which can be expressed as t_(T,i). This specified temperature canrepresent a temperature above the baseline temperature, and/or atemperature at which thermal damage can be caused. Exemplarytemperatures include 41° C., 42° C., 43° C., 44° C., 45° C., 46° C., 47°C., 48° C., 49° C., 50° C., 51° C.-60° C., 42° C.-46° C., or anyfractional temperatures or ranges therebetween. “i” can refer to a timepoint or measurement number. A constant (R) is integrated according tothe time point/measurement number and a difference between the specifictemperature t and an actual temperature to compute thermal damage.

The constant R can be defined as a constant having values that aredependent on a current temperature, and thus, in some aspects can be aconstant that varies according to a step function based on a currenttemperature. Tissue damage can be a complex function of time-temperaturehistory, and the calculation of thermal damage can compare a timerequired for thermal injury to a reference temperature, based onfindings that, for most soft tissue, a temperature above the specifiedtemperature, such as 42° C., 43° C., 44° C., 45° C. or 46° C., causesthermal injury to the tissue.

A calculation of t_(T,i) can be equated to one of various thresholdtimes that can be indicated by one or more colored lines to indicate atissue or portion of a tissue has been held at an equivalent temperatureof the specified temperature for that threshold time. Adverting back toFIG. 100, the isoline or contour line 656 is displayed so as to coincidewith a tissue or portions of a tissue that reach a first threshold.

Multiple isolines or contour lines can be simultaneously displayed inthe GUI, where each of the lines corresponds to a different threshold.Exemplary thresholds can be set at 1, 2, 3, 4, 5, 10, 15, 20, 30, 45 and60 minutes for specified temperatures of 42° C., 43° C., 44° C., 45° C.or 46° C. With such lines, such as two or three, being displayedsimultaneously or contemporaneously, a progression of treatment can bemonitored by an operator. Preferably one or more of the thresholdscorresponds to a 100% or near 100% “kill rate” in that all or generallyall biological functions of a tissue is destroyed at that amount ofexposure to energy. However, other thresholds can be set to monitortreatment.

For cooling probes, an opposing relationship is viewable via the GUI formonitoring an equivalent temperature below the baseline temperature thatindicates treatment or necrotizing of a tissue.

Through noise masking, real-time shaping is enabled to monitor treatmentthrough a graphical user interface or other display. Color maps can beutilized in conjunction with isolines and/or contour lines that indicatea treatment shape. By tracking a probe position within tissue throughfeedback, multiple data slices provided around the probe position can beprocessed to monitor treatment and view thermal data. Thus, noisemasking in combination with real-time probe feedback enables thecalculation and display of real-time shaping of a treatment region.Further, real-time shaping utilizes multiple slices of image data andnoise masking

vii. Forecasting

Forecasting errors and issues with the MRI systems and variouscomponents is preferable to avoid procedure interruption. Forecastingcan include continuous data filtration in connection with real-timeshaping data rendering.

The workstation, either alone or in combination with a workstation orprocessing system dedicated to the MRI, monitors the reception of realtime data from the MRI system. Based on statistics and averages of timedelays (e.g., a latency) in receiving data (i.e., images) from the MRIsystem, a warning signal can be issued or displayed to an operator whena delay in receiving an expected image exceeds a threshold value. Basedon a magnitude of the delay or repeating delays, the workstation candeactivate an energy output of a probe, and place the GUI of theworkstation in a standby mode.

Similarly, the workstation can monitor temperature fluctuations in oneor more of the reference points, within the patient, the MRI controlroom, the MRI system room or any other room. Excessive temperaturefluctuations of tissue within the patient or within any of the rooms canindicate issues with the various components or accessory devices.Accordingly, based on a magnitude of the fluctuations of temperature inthe reference points or any monitored area or portion of the patient,the workstation can deactivate an energy output of a probe, and placethe GUI of the workstation in a standby mode.

A signal strength from the MRI is also monitored by the workstation. Ifa signal strength is too low, temperature data is unreliable and theoperator is warned of the issue. Based on a magnitude of the signalstrength, the workstation can deactivate an energy output of a probe,and place the GUI of the workstation in a standby mode.

An image quality of the images received by the workstation can bemonitored and measured for quality. Quality measuring identifiespotentially harmful issues such as patient motion, RF noise, and otherartifacts due to external causes. For example, a non-MRI compatibledevice or equipment near the patient can cause such artifacts. Qualitymeasuring can include scanning received images to detect artifacts orunexpected pixel information. Based on image quality, the workstationcan deactivate an energy output of a probe, and place the GUI of theworkstation in a standby mode.

Once in standby mode, the workstation can automatically recover toresume treatment by selecting a new reference point and/or adjusting anoise mask, and then the operator can recommence treatment afterconfirming any data errors have been addressed and treatment of thepatient is not impaired.

The workstation, either alone or in combination with a workstation orprocessing system dedicated to the MRI, can also perform signalfiltration of MR raw data. The filtration can help identify issues thatimpact temperature sensitivity, accuracy and the ultimate prediction ofthermal dose. Features or parts of a signal that are filtered include:range, outliers, sequence, and notification packets. These features orparts are processed by an algorithm of the workstation to collect,filter, sort and weight data. A corresponding display is displayed to anoperator to inform the operator of potential issues, and allow theoperator to continue with a treatment, pause a treatment or halt atreatment. The workstation can also provide recommendations for takingaction based on predefined criteria and a history of analyzed data.

VII. Alternative Embodiment

Alternative embodiments to the probe driver and miniframe described inSections II and III will now be discussed.

As alternative to the miniframe described above, the cranial boltsdescribed in related U.S. Application No. 62/132,970, filed on Mar. 13,2015 assigned to Monteris Medical Corporation and entitled “Apparatusand Methods for Neurological Intervention” (hereinafter “the relatedcranial bolt application”), can be used for trajectory determination,alignment, and guidance of the probes described above. The relatedcranial bolt application is incorporated by reference herein in itsentirety.

The cranial bolts described in the related application can be used withthe robotic probe driver described above in place of the miniframe. Thecranial bolts work with the probe driver in the same way as theminiframe, except as discussed below.

An exemplary bolt 100 is shown in FIG. 102. The bolt 100 includes a body104 formed of a cylindrical base 108 and planar members or wings 112. Afirst end of the cylindrical base 108 includes a tapered threadedportion 116. The cylindrical base 108 also includes an opening 118extending therethrough.

The bolt 100 also includes a bushing 120 that is adjustable with respectto the body 104. The bushing 120 includes a cylindrical body 124 thatfits within, and is coaxial to, the opening 118 of the body 104. Thebushing cylindrical body 124 includes marked gradations to measure theadjustable distance with respect to the body 104 of the bolt 100. Afixing device 132 locks the bushing 120 with respect to the body 104.

The bushing 120 includes a stopper 128 positioned above the cylindricalbody 124 and a connector 136 at an opposite end to the cylindrical body124. The bushing 120 also includes an opening 140 therethrough that iscoaxial with the opening 118 such that a probe or other surgicalinstrument can be passed through the bolt 100 and into the skull, asdiscussed below.

Specifically, to use the bolt 100 in a surgical procedure, the bolt 100is aligned with and inserted into a bore hole in a patient's skull.Next, the probe driver is attached to the bushing 120 of the bolt 100.In order to attach the probe driver discussed above to the bolt 100, theprobe driver is modified to have a distal portion with a shorter stemand an appropriate internal diameter to allow mounting of the probedriver closer to the skull. In a specific embodiment, the probe driveris modified as follows.

An exemplary follower of the probe driver can be seen as referencecharacter 300 in FIG. 103. Other than the updated follower, the probedriver comprises a commander, umbilicals, and a position feedback plugthat receives position feedback signals from potentiometers within thefollower as discussed above and shown in FIG. 5. A probe can be insertedinto the follower 300, and the follower 300 can control a rotational andlongitudinal alignment of the probe as discussed above.

The follower 300 of the probe driver includes a base 304, projections308 extending from a top face of the base 304, and a stem 312 extendingfrom a bottom face of the base 304. The base 304 includes a through hole316 that aligns with an opening 320 in the stem 312. The opening 320 inthe stem 312 is wider than the diameter of the probe that passes throughthe stem 312 such that the stem 312 can be mounted on the connector 136of the bolt 100. In an exemplary embodiment, the diameter of the opening320 of the stem 312 is within a first range and the outer diameter ofthe connector 136 is within another range, provided that the follower300 and bolt 100 are sized such that the diameter of the opening 320 islarger than the outer diameter of the connector 136. The probe lockscrew 144, which is unscrewed from the bolt 100 before the follower 300is mounted on the bolt 100, can then be screwed into the through hole324 in the side of the stem 312 and then back into the connector 136 ofthe bolt 100.

After the follower 300 is attached to the bolt 100, the probe is thenattached to the follower 300 of the probe driver as discussed above. Inan exemplary embodiment, the probe lock screw 144 of the bolt 100 can befurther tightened such that it contacts the probe to help hold the probein place.

The follower 300 can also be used with bolt 200, which is described inthe related cranial bolt application and shown in FIG. 104.

In the exemplary embodiment shown in FIG. 105, the follower 300 ismounted to the bolt 200. The assembly also includes a locking sleeve 400for added stability. The locking sleeve 400 includes an opening that hasa larger diameter than the outer diameter of the stem 312 of thefollower 300 such that the locking sleeve 400 can be mounted on anoutside of the stem 312. In an assembled position, the stem 312 islocated between the connector 208 of the bolt 200 and the sleeve 400.The sleeve 400 also includes a through hole 408 such that the thumbscrew 216 passes through the through hole 408 of the sleeve 400, thenthe through hole 324 in the stem 312, and then into the hole in the sideof the connector 208 of the bolt 200.

An exemplary embodiment of the sleeve 400 is made of MRI-compatiblematerial. One example of such an MRI-compatible material is Delrin®.

An exemplary embodiment of the sleeve 400 has a mating surface thatmatches a corresponding mating surface on the bottom face of the base304 of the follower 300. For example, the top face of the sleeve 400 caninclude a recessed portion that mates with a protruding portion on thebottom face of the base 304 of the follower 300. The protruding portioncan extend outwardly from the rest of the planar bottom face and therecessed portion is recessed from the rest of the top face of the sleeve400 such that the recessed portion contacts the protruding portion andthe rest of the top face of the sleeve contacts the planar bottom faceof the base.

The protrusion and recessed portion can be positioned such that, whenthey are in contact, the through hole 408 of the locking sleeve 400aligns with the through hole 324 in the stem 312 such that the thumbscrew 216 can be screwed into both the sleeve 400 and follower 300 whenthe protrusion and recessed portion are in contact. Thus, the sleeve 400can be properly positioned with respect to the follower 300. In anexemplary embodiment, the through hole 408 of the locking sleeve 400 canonly be aligned with the through hole 324 in the stem 312 when theprotrusion and recessed portion are in contact, which prevents a userfrom incorrectly positioning the sleeve 400 with respect to the follower300.

The sleeve 400 can also be used with bolt 100 in a manner similar tothat described above with respect to bolt 200.

Dimensions of an exemplary follower 300 will now be described. In thisexemplary embodiment shown in FIGS. 105A-105C, the base 304 has a lengthof 47.3 mm and a width of 22.0 mm. The bottom face of the base 304includes a shallow cutout 328 for a fiducial marker. A center of theshallow cutout 328 is positioned 15 mm from the rear edge of the base304. The cutout 328 has a diameter of 20 mm. The projections have aheight of 71.2 mm and a width of 22 mm.

As shown in FIG. 105A, the stem 312 has a length, which is measured fromthe bottom planar face of the base 304, of 19.0 mm. In an alternativeembodiment, a follower has a medium length of 32.0 mm. In anotheralternative embodiment, the follower has a long length of 48.0 mm. Thethrough hole 324 in the stem 312 has a diameter of 4.3 mm and a centerof the through hole 324 is positioned 5.0 mm above the bottom of thestem 312. Additionally, the opening 320 has a diameter of 8.0 mm.

Compared with the follower used with the miniframe, the follower 300described in the present Section VII has a shorter stem 312.Additionally, the bolts described above have a shorter height than theminiframe. Thus, when the probe is used with the follower 300 and one ofthe bolts 100, 200, the height that the probe is mounted above thepatient's skull, also known as stack height, is reduced.

The low profile probe driver allows the probe to access multipledirections and depths within the target tissue without the need tocreate additional access, e.g., additional bores in a subject's skull.The probe driver also allows the user to precisely position, stabilizeand manipulate the probe within or in proximity to the target tissue,either remotely or manually. The probe driver is also preferablycompatible with imaging techniques used during the application of thetreatment, such as MRI. This allows not only wider access to the targettissue through a low profile system design, but also allows more targettissue to be reached and treated by allowing expanded fitting in thespace between the probe entry site (e.g., the patient's skull) and theedge of an MRI bore.

FIGS. 106A and 106B show a probe 400 mounted on the bolt 200 (FIG. 106A)and mounted on a miniframe 500 (FIG. 106B). As can be seen from thesefigures, the max distance that the probe is able to penetrate within thepatient's skull is 47 mm greater in FIG. 106A due to the shorter heightof the bolt 200 and the shorter stem 312 of the follower 300.

VIII. Conclusion

The procedures and routines described herein can be embodied as asystem, method or computer program product, and can be executed via oneor more dedicated circuits or programmed processors. Accordingly, thedescriptions provided herein may take the form of exclusively hardware,exclusively software executed on hardware (including firmware, residentsoftware, micro-code, etc.), or through a combination of dedicatedhardware components and general processors that are configured byspecific algorithms and process codes. Hardware components are referredto as a “circuit,” “module,” “unit,” “device,” or “system.” Executablecode that is executed by hardware is embodied on a tangible memorydevice, such as a computer program product. Examples include CDs, DVDs,flash drives, hard disk units, ROMs, RAMs and other memory devices.

Reference has been made to flowchart illustrations and block diagrams ofmethods, systems and computer program products according toimplementations of this disclosure. Aspects thereof are implemented bycomputer program instructions. These computer program instructions maybe provided to a processor of a general purpose computer, specialpurpose computer, or other programmable data processing apparatus toproduce a machine, such that the instructions, which execute via theprocessor of the computer or other programmable data processingapparatus, create means for implementing the functions/acts specified inthe flowchart and/or block diagram block or blocks.

These computer program instructions may also be stored in acomputer-readable medium that can direct a computer or otherprogrammable data processing apparatus to function in a particularmanner, such that the instructions stored in the computer-readablemedium produce an article of manufacture including instruction meanswhich implement the function/act specified in the flowchart and/or blockdiagram block or blocks.

The computer program instructions may also be loaded onto a computer orother programmable data processing apparatus to cause a series ofoperational steps to be performed on the computer or other programmableapparatus to produce a computer implemented process such that theinstructions which execute on the computer or other programmableapparatus provide processes for implementing the functions/actsspecified in the flowchart and/or block diagram block or blocks.

A number of implementations have been described. Nevertheless, it willbe understood that various modifications may be made without departingfrom the spirit and scope of this disclosure. For example, preferableresults may be achieved if the steps of the disclosed techniques wereperformed in a different sequence, if components in the disclosedsystems were combined in a different manner, or if the components werereplaced or supplemented by other components. The functions, processesand algorithms described herein may be performed in hardware or softwareexecuted by hardware, including computer processors and/or programmablecircuits configured to execute program code and/or computer instructionsto execute the functions, processes and algorithms described herein.Additionally, some implementations may be performed on modules orhardware not identical to those described. Accordingly, otherimplementations are within the scope that may be claimed.

A system for effecting treatment to a tissue can include: an automateddrive mechanism including a holder to hold a treatment device, whereinthe drive mechanism is coupled to one or more wires such that atranslation of the one or more wires effects one or more of alongitudinal displacement of the holder and a rotation of the holder;and a controller including an input interface to process positioncontrol signals for setting a position of the treatment device, and anoutput interface to translate the one or more wires based on theposition control signals.

The system can further include: a guide mechanism that is attachable toa surface of a patient, wherein the guide mechanism includes a basestructure that is configured to remain stationary relative to thepatient when the guide mechanism is attached to the surface of thepatient in a locked state, the guide mechanism includes a tilt portionthat is coupled to the base structure, the tilt portion is structured soas to hold the drive mechanism at a position that is separated from thesurface of the patient, and the tilt portion provides an adjustable tiltbetween a trajectory of the drive mechanism and the base structure. Theguide mechanism can further include a rotation portion that provides anadjustable rotation of the tilt portion relative to the base structure.

The drive mechanism can be motorless and consists of thermal imagingcompatible components.

The controller can be configured to process a sequence of the positioncontrol signals to: move the holder to a first position for effectingthe treatment to the tissue at a first portion of the tissue thatcoincides with the first position; and move the holder to a secondposition for effecting the treatment to the tissue at a second portionof the tissue that coincides with the second position. The system canfurther include a workstation to transmit the position control signalsto the controller and to display thermometry images of the tissue. Theworkstation can continuously display the thermometry images of thetissue during the treatment to the tissue at the first and secondportions of the tissue, and while the holder moves between the first andsecond positions.

The system can further include an energy emission probe as the treatmentdevice, wherein the probe generates a plurality of different outputpatterns. The probe can include a first laser fiber for outputting asymmetrical output pattern with respect to a longitudinal axis of thefirst laser fiber, and the probe can include a second laser fiber foroutputting an asymmetrical output pattern with respect to a longitudinalaxis of the second laser fiber.

The system can further include: an energy source to generate energy forthe probe; and a workstation to transmit the position control signals tothe controller, and to transmit energy control signals to the energysource, wherein the workstation is configured to process a sequence ofthe energy control signals to: effect a symmetrical treatment to thetissue with the probe; and effect an asymmetrical treatment to thetissue with the probe after the symmetrical treatment.

The system can also include: a laser source to generate laser energy forthe laser probe; and a workstation to transmit the position controlsignals to the controller, and to transmit laser control signals to thelaser source, wherein the workstation is configured to process asequence of the position and laser control signals to: move the holderto a first position for effecting the treatment to the tissue at a firstportion of the tissue that coincides with the first position; effect asymmetrical treatment to the first portion of the tissue with the firstlaser fiber; move the holder to a second position for effecting thetreatment to the tissue at a second portion of the tissue that coincideswith the second position; and effect an asymmetrical treatment to thesecond portion of the tissue with the second laser fiber. Theworkstation can be configured to display thermometry images of thetissue continuously throughout processing of the sequence of theposition and laser control signals and throughout moving the holder andeffecting the symmetrical and asymmetrical treatments.

The system can include an imaging system to output images of the tissueand the treatment device, including thermometry images of the tissue, inreal time, continuously throughout one or more steps of effecting thetreatment to the tissue; and a workstation to transmit the positioncontrol signals to the controller based on one or more of the images, asthe images are received by the workstation in real time, and to display,in real time, one or more of the images throughout the one or more stepsof effecting the treatment to the tissue.

The workstation can be configured to display, in real time, thethermometry images of the tissue with the images of the tissue and thetreatment device continuously throughout a processing of the positioncontrol signals and throughout moving the holder and effecting thetreatment to the tissue.

The workstation can be configured to process, in real time, the imagesof the tissue and the treatment device and the thermometry images of thetissue to forecast errors or interruptions in the treatment to thetissue and display a corresponding warning.

The system can further include an energy emission probe as the treatmentdevice, the energy emission probe including one or more emittersselected from: a laser fiber, a radiofrequency emitter, a high-intensityfocused ultrasound emitter, a microwave emitter, a cryogenic coolingdevice, and a photodynamic therapy light emitter. The energy emissionprobe can include a plurality of the emitters. The plurality of theemitters can be longitudinally spaced with respect to a longitudinalaxis of the energy emission probe.

The system can further include a guide sheath including a plurality ofprobes of different modalities as the treatment device, wherein themodalities include one or more of: laser, radiofrequency, high-intensityfocused ultrasound, microwave, cryogenic, photodynamic therapy, chemicalrelease and drug release. The guide sheath can include one or moreoff-axis holes for positioning an emitting point of one or more of theplurality of probes at an off-axis angle.

The invention claimed is:
 1. A system for effecting treatment to atissue, comprising: a motorless drive mechanism that is compatible withand can operate within an operational field of a medical imaging systemto image the tissue without substantially disrupting imaging performedby the medical imaging system, the motorless drive mechanism including aholder to hold a treatment device to treat the tissue, and a first wiretranslation mechanism that couples one or more wires to the holder, suchthat a translation of the one or more wires effects one or more of alongitudinal displacement of the holder and a rotation of the holder; abase unit that is coupled to the motorless drive mechanism by the one ormore wires, the base unit including a second wire translation mechanismto translate the one or more wires; an electronic controller includingan input interface to receive position control signals for setting aposition of the treatment device, and an output interface that iscoupled to the second wire translation mechanism of the base unit, suchthat the output interface effects movements of the second wiretranslation mechanism to translate the one or more wires based on theposition control signals received by the input interface to effectmovements of the first wire translation mechanism, such that one or moreof the longitudinal displacement of the holder and the rotation of theholder are effected based on the position control signals received bythe input interface; and an energy emission probe as the treatmentdevice including a first laser fiber and a second laser fiber foroutputting a plurality of different output patterns. wherein the firstlaser fiber outputs a symmetrical output pattern with respect to alongitudinal axis of the first laser fiber, and the second laser fiberoutputs an asymmetrical output pattern with respect to a longitudinalaxis of the second laser fiber.
 2. The system according to claim 1,further comprising a guide assembly that is attachable to a surface of apatient, the guide assembly including: a base structure that remainsstationary relative to the patient when the guide assembly is attachedto the surface of the patient in a locked state; and a tilt portion thatis coupled to the base structure, the tilt portion that holds themotorless drive mechanism at a position that is separated from thesurface of the patient, and the tilt portion providing an adjustabletilt between a trajectory of the motorless drive mechanism and the basestructure when the base structure remains stationary relative to thepatient.
 3. The system according to claim 2, wherein the guide assemblyfurther includes a rotation portion that provides an adjustable rotationof the tilt portion relative to the base structure.
 4. The systemaccording to claim 1, wherein: the medical imaging system is a magneticresonance imaging (MRI) system that includes a thermal imaging function,and the motorless drive mechanism consists of MRI and thermal imagingcompatible materials and structures.
 5. The system according to claim 1,wherein: the electronic controller is to process a sequence of theposition control signals to move the holder to a first position foreffecting the treatment to the tissue at a first portion of the tissuethat coincides with the first position, and move the holder, after theeffecting the treatment to the tissue as the first portion, to a secondposition for effecting the treatment to the tissue at a second portionof the tissue that coincides with the second position; and theelectronic controller is to cause the holder to move from the firstposition to the second position while the medical imaging systemcontinuously images the tissue.
 6. The system according to claim 5,further comprising: a workstation to transmit the position controlsignals to the controller and to display thermometry images of thetissue.
 7. The system according to claim 6, wherein the workstationcontinuously displays the thermometry images of the tissue during thetreatment to the tissue at the first and second portions of the tissue,while the medical imaging system continuously images the tissue, andwhile the holder moves between the first and second positions.
 8. Thesystem according to claim 1, further comprising: an energy source togenerate energy for the probe; and a workstation to transmit theposition control signals to the electronic controller, and to transmitenergy control signals to the energy source, wherein the workstation isto process a sequence of the energy control signals to effect asymmetrical treatment to the tissue with the probe, and effect anasymmetrical treatment to the tissue with the probe after thesymmetrical treatment.
 9. The system according to claim 1, furthercomprising: a laser source to generate laser energy for the laser probe;and a workstation to transmit the position control signals to thecontroller, and to transmit laser control signals to the laser source,wherein the workstation is to process a sequence of the position andlaser control signals to move the holder to a first position foreffecting the treatment to the tissue at a first portion of the tissuethat coincides with the first position, effect a symmetrical treatmentto the first portion of the tissue with the first laser fiber, move theholder to a second position for effecting the treatment to the tissue ata second portion of the tissue that coincides with the second position,and effect an asymmetrical treatment to the second portion of the tissuewith the second laser fiber.
 10. The system according to claim 9,wherein the workstation is to display thermometry images of the tissuecontinuously throughout processing of the sequence of the position andlaser control signals and throughout moving the holder and effecting thesymmetrical and asymmetrical treatments.
 11. The system according toclaim 1, further comprising: the medical imaging system to output imagesof the tissue and the treatment device, including thermometry images ofthe tissue, in real time, continuously throughout one or more steps ofeffecting the treatment to the tissue; and a workstation to transmit theposition control signals to the controller based on one or more of theimages, as the images are received by the workstation in real time, andto display, in real time, one or more of the images throughout the oneor more steps of effecting the treatment to the tissue.
 12. The systemaccording to claim 11, wherein the workstation is to display, in realtime, the thermometry images of the tissue with the images of the tissueand the treatment device continuously throughout a processing of theposition control signals and throughout moving the holder and effectingthe treatment to the tissue.
 13. The system according to claim 11,wherein the workstation is to process, in real time, the images of thetissue and the treatment device and the thermometry images of the tissueto forecast errors or interruptions in the treatment to the tissue anddisplay a corresponding warning.
 14. The system according to claim 1,wherein the energy emission probe includes a plurality of the emitters.15. The system according to claim 14, wherein the plurality of theemitters are longitudinally spaced with respect to a longitudinal axisof the energy emission probe.
 16. The system according to claim 1,further comprising: a guide sheath including a plurality of probes ofdifferent modalities as the treatment device, wherein the modalitiesinclude one or more of: laser, radiofrequency, high-intensity focusedultrasound, microwave, cryogenic, photodynamic therapy, chemical releaseand drug release.
 17. The system according to claim 16, wherein theguide sheath includes one or more off-axis holes for positioning anemitting point of one or more of the plurality of probes at an off-axisangle.